Visual Studio compiles some files every time (even when no changes are made)

I've been developing an application on VS2008 and everything went very well. I made some alterations, on the name of the solution and projects, and that's about when I started going crazy with the following behavior:

• I clean my solution;
• Every file is recompiled (normal up to here);
• I make no changes whatsoever in any file and VS compile a set of files again;
• Still with no changes made, the same files get recompiled every time.

If somebody has an idea of might be going on, that would be fant开发者_Go百科astic. If not, what kind of tests can I do to investigate this further?

Thanks

EDIT:

• The language used is C++ with CUDA extensions;
• The files being compiled every time are .cu files

Probably those file had had file modification date in the future, and after you saved them their date became in the past.