Internal Compiler Error caused by Visual Studio project?

Update on a recent post: http://answers.unity3d.com/questions/554128/internal-compiler-error-14.html

This problem has arisen on several different projects, with not always the same internal compiler error popping up.

If I don't open my script using the Visual Studio solution/project it seems to work. Opening and editing the files individually doesn't cause any errors. Only when the solution is generated and Unity uses that to compile, the error pops up.

So I assume there's an issue with the solution/project files, and how it's using it. I don't know the fix, but maybe this info can help. I still need a solution though as opening files individually is harder to work with.