I have the same error, except it's crashing Visual Studio. If I try to run the unit tests or look at my Visual Studio test settings, Visual Studio immediately crashes with:
Application: devenv.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileLoadException
Stack:
at TypeMock.ArrangeActAssert.IsolatedAttribute.Finalize()
This is on Windows 7 Professional (x64). I have tried Typemock Isolator for SharePoint 7.0.4.0 and 7.0.5.0. I checked the GAC and only have Typemock.Interceptors installed.