Forums / Cotonti / Support / PFS Problem

Hi.
I installed Cotonti for a little project of mine.
I am having a problem with PFS.
I will upload a file (.zip) and I get this:
"gnextop_theme.zip : This is not a valid zip file."
I have tried other files, and I get the same thing. I even reran the sql for the site and still no luck. It uploads images, but not zips.