Since this sounds like an isolated incident, you might want to contact your web host support for help. Maybe something's not right on the server.

Also try reuploading the groups.php in BINARY or worse case scenario, reinstall vShare. Try installing it at a "test" location on the server an see if you get the same results. If you don't have a problem with vShare at the test location on the same server, then you know it's an install issue with the working site. If you do have the same problem then it's probably a host issue (my guess)