Okay, so after you rebuild the .lib project, what do you do with the .lib file? I assume since you are getting linker errors and not a "can't find the .lib file" error, it must be somewhere in a VS Lib directory.

Sorry if this is a dumb question, but are you sure that it is the most recent version of the .lib file that is being linked into your test project, and not a previous version of the .lib?

Can't really think of anything else to suggest based on the problems you describe.