diff --git a/src/ImageProcessor.Web/NET45/Caching/DiskCache.cs b/src/ImageProcessor.Web/NET45/Caching/DiskCache.cs
index be6b88744..c6300c64d 100644
--- a/src/ImageProcessor.Web/NET45/Caching/DiskCache.cs
+++ b/src/ImageProcessor.Web/NET45/Caching/DiskCache.cs
@@ -49,14 +49,14 @@ namespace ImageProcessor.Web.Caching
         private const int MaxFilesCount = 100;
 
         /// <summary>
-        /// The absolute path to virtual cache path on the server.
+        /// The virtual cache path.
         /// </summary>
-        private static readonly string AbsoluteCachePath = HostingEnvironment.MapPath(ImageProcessorConfiguration.Instance.VirtualCachePath);
+        private static readonly string VirtualCachePath = ImageProcessorConfiguration.Instance.VirtualCachePath;
 
         /// <summary>
-        /// The request for the image.
+        /// The absolute path to virtual cache path on the server.
         /// </summary>
-        private readonly HttpRequest request;
+        private static readonly string AbsoluteCachePath = HostingEnvironment.MapPath(ImageProcessorConfiguration.Instance.VirtualCachePath);
 
         /// <summary>
         /// The request path for the image.
@@ -72,15 +72,22 @@ namespace ImageProcessor.Web.Caching
         /// The image name
         /// </summary>
         private readonly string imageName;
+
+        /// <summary>
+        /// The physical cached path.
+        /// </summary>
+        private string physicalCachedPath;
+
+        /// <summary>
+        /// The virtual cached path.
+        /// </summary>
+        private string virtualCachedPath;
         #endregion
 
         #region Constructors
         /// <summary>
         /// Initializes a new instance of the <see cref="DiskCache"/> class.
         /// </summary>
-        /// <param name="request">
-        /// The request for the image.
-        /// </param>
         /// <param name="requestPath">
         /// The request path for the image.
         /// </param>
@@ -90,53 +97,41 @@ namespace ImageProcessor.Web.Caching
         /// <param name="imageName">
         /// The image name.
         /// </param>
-        public DiskCache(HttpRequest request, string requestPath, string fullPath, string imageName)
+        public DiskCache(string requestPath, string fullPath, string imageName)
         {
-            this.request = request;
             this.requestPath = requestPath;
             this.fullPath = fullPath;
             this.imageName = imageName;
+
+            // Get the physical and virtual paths.
+            this.GetCachePaths();
         }
         #endregion
 
-        #region Methods
-        #region Internal
         /// <summary>
-        /// Gets the full transformed cached path for the image. 
-        /// The images are stored in paths that are based upon the SHA1 of their full request path
-        /// taking the individual characters of the hash to determine their location.
-        /// This allows us to store millions of images.
+        /// Gets the cached path.
         /// </summary>
-        /// <returns>The full cached path for the image.</returns>
-        internal Task<string> GetCachePathAsync()
+        public string CachedPath
         {
-            return TaskHelpers.Run<string>(this.GetCachePath);
+            get
+            {
+                return this.physicalCachedPath;
+            }
         }
 
         /// <summary>
-        /// Gets the virtual path to the cached processed image.
+        /// Gets the cached path.
         /// </summary>
-        /// <param name="cachedPath">
-        /// The path to the cached image.
-        /// </param>
-        /// <returns>
-        /// The virtual path to the cached processed image.
-        /// </returns>
-        internal string GetVirtualCachedPath(string cachedPath)
+        public string VirtualCachedPath
         {
-            string applicationPath = this.request.PhysicalApplicationPath;
-            string virtualDir = this.request.ApplicationPath;
-            virtualDir = virtualDir == "/" ? virtualDir : (virtualDir + "/");
-
-            if (applicationPath != null)
+            get
             {
-                return cachedPath.Replace(applicationPath, virtualDir).Replace(@"\", "/");
+                return this.virtualCachedPath;
             }
-
-            throw new InvalidOperationException(
-                "We can only map an absolute back to a relative path if the application path is available.");
         }
 
+        #region Methods
+        #region Internal
         /// <summary>
         /// Adds an image to the cache.
         /// </summary>
@@ -256,15 +251,13 @@ namespace ImageProcessor.Web.Caching
         }
 
         /// <summary>
-        /// Gets the full transformed cached path for the image. 
+        /// Gets the full transformed cached paths for the image. 
         /// The images are stored in paths that are based upon the SHA1 of their full request path
         /// taking the individual characters of the hash to determine their location.
         /// This allows us to store millions of images.
         /// </summary>
-        /// <returns>The full cached path for the image.</returns>
-        private string GetCachePath()
+        private void GetCachePaths()
         {
-            string cachedPath = string.Empty;
             string streamHash = string.Empty;
 
             if (AbsoluteCachePath != null)
@@ -302,16 +295,16 @@ namespace ImageProcessor.Web.Caching
 
                 // Collision rate of about 1 in 10000 for the folder structure.
                 string pathFromKey = string.Join("\\", encryptedName.ToCharArray().Take(6));
+                string virtualPathFromKey = pathFromKey.Replace(@"\", "/");
 
                 string cachedFileName = string.Format(
                     "{0}.{1}",
                     encryptedName,
                     !string.IsNullOrWhiteSpace(parsedExtension) ? parsedExtension.Replace(".", string.Empty) : fallbackExtension);
 
-                cachedPath = Path.Combine(AbsoluteCachePath, pathFromKey, cachedFileName);
+                this.physicalCachedPath = Path.Combine(AbsoluteCachePath, pathFromKey, cachedFileName);
+                this.virtualCachedPath = Path.Combine(VirtualCachePath, virtualPathFromKey, cachedFileName).Replace(@"\", "/");
             }
-
-            return cachedPath;
         }
 
         /// <summary>
diff --git a/src/ImageProcessor.Web/NET45/HttpModules/ImageProcessingModule.cs b/src/ImageProcessor.Web/NET45/HttpModules/ImageProcessingModule.cs
index db378fae4..0f4db86f3 100644
--- a/src/ImageProcessor.Web/NET45/HttpModules/ImageProcessingModule.cs
+++ b/src/ImageProcessor.Web/NET45/HttpModules/ImageProcessingModule.cs
@@ -13,7 +13,6 @@ namespace ImageProcessor.Web.HttpModules
     #region Using
     using System;
     using System.Collections.Concurrent;
-    using System.Collections.Generic;
     using System.Diagnostics.CodeAnalysis;
     using System.IO;
     using System.Linq;
@@ -157,12 +156,11 @@ namespace ImageProcessor.Web.HttpModules
         /// The id representing the <see cref="T:System.Threading.SemaphoreSlim"/>.
         /// </param>
         /// <returns>
-        /// The <see cref="T:System.Threading.Mutex"/> for the given id.
+        /// The <see cref="T:System.Threading.SemaphoreSlim"/> for the given id.
         /// </returns>
         private static SemaphoreSlim GetSemaphoreSlim(string id)
         {
-            SemaphoreSlim semaphore = SemaphoreSlims.GetOrAdd(id, new SemaphoreSlim(1, 1));
-            return semaphore;
+            return SemaphoreSlims.GetOrAdd(id, new SemaphoreSlim(1, 1));
         }
 
         /// <summary>
@@ -179,12 +177,6 @@ namespace ImageProcessor.Web.HttpModules
             if (disposing)
             {
                 // Dispose of any managed resources here.
-                foreach (KeyValuePair<string, SemaphoreSlim> semaphore in SemaphoreSlims)
-                {
-                    semaphore.Value.Dispose();
-                }
-
-                SemaphoreSlims.Clear();
             }
 
             // Call the appropriate methods to clean up
@@ -346,15 +338,15 @@ namespace ImageProcessor.Web.HttpModules
                 }
 
                 // Create a new cache to help process and cache the request.
-                DiskCache cache = new DiskCache(request, requestPath, fullPath, imageName);
-                string cachedPath = await cache.GetCachePathAsync();
+                DiskCache cache = new DiskCache(requestPath, fullPath, imageName);
+                string cachedPath = cache.CachedPath;
 
                 // Since we are now rewriting the path we need to check again that the current user has access
                 // to the rewritten path.
                 // Get the user for the current request
                 // If the user is anonymous or authentication doesn't work for this suffix avoid a NullReferenceException 
                 // in the UrlAuthorizationModule by creating a generic identity.
-                string virtualCachedPath = cache.GetVirtualCachedPath(cachedPath);
+                string virtualCachedPath = cache.VirtualCachedPath;
 
                 IPrincipal user = context.User ?? new GenericPrincipal(new GenericIdentity(string.Empty, string.Empty), new string[0]);
 
@@ -362,7 +354,7 @@ namespace ImageProcessor.Web.HttpModules
                 PermissionSet permission = new PermissionSet(PermissionState.None);
                 permission.AddPermission(new AspNetHostingPermission(AspNetHostingPermissionLevel.Unrestricted));
                 bool hasPermission = permission.IsSubsetOf(AppDomain.CurrentDomain.PermissionSet);
-                
+
                 bool isAllowed = true;
 
                 // Run the rewritten path past the authorization system again.
@@ -385,17 +377,19 @@ namespace ImageProcessor.Web.HttpModules
                         {
                             if (isRemote)
                             {
-                                Uri uri = new Uri(requestPath + "?" + urlParameters);
-
-                                RemoteFile remoteFile = new RemoteFile(uri, false);
-
-                                // Prevent response blocking.
-                                WebResponse webResponse = await remoteFile.GetWebResponseAsync().ConfigureAwait(false);
-
                                 SemaphoreSlim semaphore = GetSemaphoreSlim(cachedPath);
+#if NET45 && !__MonoCS__
+                                await semaphore.WaitAsync();
+#else
+                                semaphore.Wait();
+#endif
                                 try
                                 {
-                                    semaphore.Wait();
+                                    Uri uri = new Uri(requestPath + "?" + urlParameters);
+                                    RemoteFile remoteFile = new RemoteFile(uri, false);
+
+                                    // Prevent response blocking.
+                                    WebResponse webResponse = await remoteFile.GetWebResponseAsync().ConfigureAwait(false);
 
                                     using (MemoryStream memoryStream = new MemoryStream())
                                     {
@@ -435,19 +429,22 @@ namespace ImageProcessor.Web.HttpModules
                             }
                             else
                             {
-                                // Check to see if the file exists.
-                                // ReSharper disable once AssignNullToNotNullAttribute
-                                FileInfo fileInfo = new FileInfo(requestPath);
-
-                                if (!fileInfo.Exists)
-                                {
-                                    throw new HttpException(404, "No image exists at " + fullPath);
-                                }
-
                                 SemaphoreSlim semaphore = GetSemaphoreSlim(cachedPath);
+#if NET45 && !__MonoCS__
+                                await semaphore.WaitAsync();
+#else
+                                semaphore.Wait();
+#endif
                                 try
                                 {
-                                    semaphore.Wait();
+                                    // Check to see if the file exists.
+                                    // ReSharper disable once AssignNullToNotNullAttribute
+                                    FileInfo fileInfo = new FileInfo(requestPath);
+
+                                    if (!fileInfo.Exists)
+                                    {
+                                        throw new HttpException(404, "No image exists at " + fullPath);
+                                    }
 
                                     // Process the Image
                                     imageFactory.Load(requestPath)
diff --git a/src/ImageProcessor/Imaging/Formats/GifFormat.cs b/src/ImageProcessor/Imaging/Formats/GifFormat.cs
index 83904225b..dffccb99b 100644
--- a/src/ImageProcessor/Imaging/Formats/GifFormat.cs
+++ b/src/ImageProcessor/Imaging/Formats/GifFormat.cs
@@ -86,7 +86,7 @@ namespace ImageProcessor.Imaging.Formats
                     foreach (GifFrame frame in info.GifFrames)
                     {
                         factory.Image = frame.Image;
-						frame.Image = quantizer.Quantize(processor.Invoke(factory));
+                        frame.Image = quantizer.Quantize(processor.Invoke(factory));
                         encoder.AddFrame(frame);
                     }
                 }
diff --git a/src/TestWebsites/NET45/Test_Website_NET45/Web.config b/src/TestWebsites/NET45/Test_Website_NET45/Web.config
index 67e336777..8cfc303d3 100644
--- a/src/TestWebsites/NET45/Test_Website_NET45/Web.config
+++ b/src/TestWebsites/NET45/Test_Website_NET45/Web.config
@@ -6,17 +6,17 @@
 
 <configuration>
   <configSections>
-    <!--<sectionGroup name="imageProcessor">
+    <sectionGroup name="imageProcessor">
       <section name="security" requirePermission="false" type="ImageProcessor.Web.Configuration.ImageSecuritySection, ImageProcessor.Web"/>
       <section name="processing" requirePermission="false" type="ImageProcessor.Web.Configuration.ImageProcessingSection, ImageProcessor.Web"/>
       <section name="cache" requirePermission="false" type="ImageProcessor.Web.Configuration.ImageCacheSection, ImageProcessor.Web"/>
-    </sectionGroup>-->
+    </sectionGroup>
   </configSections>
-  <!--<imageProcessor >
+  <imageProcessor >
     <security configSource="config\imageprocessor\security.config"/>
     <cache configSource="config\imageprocessor\cache.config"/>
     <processing configSource="config\imageprocessor\processing.config"/>
-  </imageProcessor>-->
+  </imageProcessor>
   <appSettings>
     <add key="webpages:Version" value="2.0.0.0" />
     <add key="webpages:Enabled" value="false" />