We\'re using MS Visual Studio 2008.
TFS seems to take into account the creation date of a file or something, to determine whether the files should be committed.
Take a look at the tfpt scripts. I think the following is what you are looking for:
TFPT.exe uu /r
The UU is Undo Unchanged and the /r is the recursive flag. Take a look here: http://blogs.msdn.com/buckh/archive/2005/11/16/493401.aspx