I haven't checked tehm all, but the few that I did check were all flv files. I think what may have happened is that there is sometimes a "Use Download Manager" option. ul.to automatically adds a check in the box so that if you aren't paying attention, you download the exe for their download manager.
HAHAHA, Idiot, flv files are video files, it says it in the name, flv = flash video, executable files are exe, executable, only exe files are executables, I love when the retarded make like they know what the real world is all about then broadcast there ignorance