diff --git a/src/AddIns/BackendBindings/WixBinding/Project/Src/WixBinaries.cs b/src/AddIns/BackendBindings/WixBinding/Project/Src/WixBinaries.cs
index 485d78dbb3..9d44bc4acb 100644
--- a/src/AddIns/BackendBindings/WixBinding/Project/Src/WixBinaries.cs
+++ b/src/AddIns/BackendBindings/WixBinding/Project/Src/WixBinaries.cs
@@ -99,7 +99,9 @@ namespace ICSharpCode.WixBinding
 				document.Load(textFileReader.Create(fileName));
 				document.FileName = fileName;
 				foreach (WixBinaryElement element in document.GetBinaries()) {
-					binaries.Add(element.Id, element.FileName);
+					if (!binaries.ContainsKey(element.Id)) {
+						binaries.Add(element.Id, element.FileName);
+					}
 				}
 			} catch (FileNotFoundException) {
 			} catch (XmlException) {
diff --git a/src/AddIns/BackendBindings/WixBinding/Test/Document/DuplicateBinaryIdTestFixture.cs b/src/AddIns/BackendBindings/WixBinding/Test/Document/DuplicateBinaryIdTestFixture.cs
new file mode 100644
index 0000000000..5a718d116c
--- /dev/null
+++ b/src/AddIns/BackendBindings/WixBinding/Test/Document/DuplicateBinaryIdTestFixture.cs
@@ -0,0 +1,92 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Matthew Ward" email="mrward@users.sourceforge.net"/>
+//     <version>$Revision$</version>
+// </file>
+
+using ICSharpCode.WixBinding;
+using ICSharpCode.SharpDevelop.Project;
+using NUnit.Framework;
+using System;
+using System.Drawing;
+using System.Collections.Generic;
+using System.IO;
+using WixBinding.Tests.Utils;
+
+namespace WixBinding.Tests.Document
+{
+	/// <summary>
+	/// Tests that WixBinaries class does not try to add the same binary id to the hash table.
+	/// </summary>
+	[TestFixture]
+	public class DuplicateBinaryIdTestFixture : ITextFileReader
+	{
+		WixBinaries binaries;
+		string projectDirectory;
+
+		[TestFixtureSetUp]
+		public void SetUpFixture()
+		{			
+			WixProject p = WixBindingTestsHelper.CreateEmptyWixProject();
+			projectDirectory = p.Directory;
+			p.Name = "MySetup";
+			
+			FileProjectItem item = new FileProjectItem(p, ItemType.Compile);
+			item.Include = "Setup.wxs";
+			string docFileName = item.FileName;
+			ProjectService.AddProjectItem(p, item);
+						
+			item = new FileProjectItem(p, ItemType.Compile);
+			item.Include = "Binaries.wxs";
+			ProjectService.AddProjectItem(p, item);
+
+			WixDocument doc = new WixDocument(p);
+			doc.FileName = docFileName;
+			doc.LoadXml(GetMainWixXml());
+			
+			binaries = new WixBinaries(doc, this);
+		}
+		
+		
+		[Test]
+		public void GetDialogBitmapFileName()
+		{
+			string expectedFileName = Path.Combine(projectDirectory, "Bitmaps/Dialog.bmp");
+			Assert.AreEqual(expectedFileName, binaries.GetBinaryFileName("Dialog"));
+		}
+		
+		
+		public TextReader Create(string fileName)
+		{
+			fileName = Path.GetFileName(fileName);
+			if (fileName == "Binaries.wxs") {
+				return new StringReader(GetWixFragmentXml());
+			}
+			return new StringReader(GetMainWixXml());
+		}
+		
+		string GetMainWixXml()
+		{
+			return "<Wix xmlns=\"http://schemas.microsoft.com/wix/2006/wi\">\r\n" +
+				"\t<Product Name=\"MySetup\" \r\n" +
+				"\t         Manufacturer=\"\" \r\n" +
+				"\t         Id=\"F4A71A3A-C271-4BE8-B72C-F47CC956B3AA\" \r\n" +
+				"\t         Language=\"1033\" \r\n" +
+				"\t         Version=\"1.0.0.0\">\r\n" +
+				"\t\t<Package Id=\"6B8BE64F-3768-49CA-8BC2-86A76424DFE9\"/>\r\n" +
+				"\t</Product>\r\n" +
+				"</Wix>";
+		}
+		
+		string GetWixFragmentXml()
+		{
+			return "<Wix xmlns=\"http://schemas.microsoft.com/wix/2006/wi\">\r\n" +
+				"\t<Fragment>\r\n" +
+				"\t\t<Binary Id='Dialog' SourceFile='Bitmaps/Dialog.bmp'/>\r\n" +
+				"\t\t<Binary Id='Dialog' SourceFile='Bitmaps/Dialog.bmp'/>\r\n" +
+				"\t</Fragment>\r\n" +
+				"</Wix>";
+		}
+	}
+}
diff --git a/src/AddIns/BackendBindings/WixBinding/Test/WixBinding.Tests.csproj b/src/AddIns/BackendBindings/WixBinding/Test/WixBinding.Tests.csproj
index 6b8e1ffac1..34f9722c90 100644
--- a/src/AddIns/BackendBindings/WixBinding/Test/WixBinding.Tests.csproj
+++ b/src/AddIns/BackendBindings/WixBinding/Test/WixBinding.Tests.csproj
@@ -50,6 +50,7 @@
   <ItemGroup>
     <Compile Include="AssemblyInfo.cs" />
     <Compile Include="Diff\MissingDirectoryTestFixture.cs" />
+    <Compile Include="Document\DuplicateBinaryIdTestFixture.cs" />
     <Compile Include="Document\GenerateComponentIdFromDirectoryWithDotsTestFixture.cs" />
     <Compile Include="Document\NewWixFileElementTests.cs" />
     <Compile Include="Gui\AddDialogsToSetupDialogListTestFixture.cs" />