Mike,
I just got finished testing on a Win2K Pro SP2 with an NTFS. Works fine on both a text file and an exe.
There are two possible issues here. One is that if the file resides on a network rather than the local drive you may be limited in the range of the time stamp. The other involves NTFS security. If you do not have full access (administrative level), you may encounter some problems here. So I'd suggest that if you're using an NTFS drive that you check the security rights on the files.
George
Ubi caritas et amor, deus ibi est