I seem to have stumbled over a bug in Visual Studio 2005, when I sign a  
Visual Studio Add-in you I get the following error:

Warning 1 Option 'keyfile' overrides attribute  
'System.Reflection.AssemblyKeyFileAttribute' given in a source file or  
added module Serialiser

This would appear to be because the project is saying that its signed, yet  
the AssemblyInfo.cs is saying that its not. This would appear to be  
because the code for assemblyinfo.cs is not the same as the "new version"  
that all other projects use. After an afternoon of trying to figure out  
what was wrong, my trusty side-kick and I managed to work it out.

The resolution is simple, choose from the following:
- Copy and paste the assemblyinfo.cs from another project (under the  
Project Properties folder, update the assembly details at the top, then  
generate yourself a new GUID – compile and sigh in relief :) OR
- Comment out the last two lines of your assemblyinfo.cs file.

Hopefully this ends up in google soonish as there was only one match which  
was a subversion log when I searched for the error.

Mark Harris
IT Vision
http://issus.livejournal.com

((Note: This has been posted over in  
microsoft.public.dotnet.languages.csharp as well.))