I have a little project, and I want to have 2 compiled versions of that project:
I've been able to solve this problem by making sure that I do not reference assemblies from the GAC. Instead, I've created a 'lib' directory in my project that contains the 3rd party assemblies. In my solution, I reference the 3rd party assemblies from there, and set copy local==True.
Next to that, you must also make sure that in your csproj file, the referenced assemblies have a Private tag whose value is set to true. Like this:
False
...
True