Thanks Joe for setting this one straight.
Eric, What I was referring to has to do with alternate data streams in NTFS. Occasionally, NTFS will block a file that has been downloaded using Internet Explorer (or unzipped using Windows Explorer...sometimes) because IE or Windows will automatically attach a Zone.Identifier=3 stream to the file. This Zone.Identifier tells NTFS that it doesn't know where the file came from. This is supposed to be one of those last ditch effort security features that usually just causes admins a bunch of heart-ache. I have seen it save a couple people from using/running very dangerous stuff on their computers.
You probably will not run into this issue if you are copying your files to your server via FTP because the FTP protocol doesn't recognize Streams and thus removes them. I have this issue on occassion but I not as much since I quit using the built-in Windows ZIP utility.
Sorry to get you running in the wrong direction.
-Joe D.