I would not recommend mounting it without all the screws correctly. You could risk having the unit fall. I don't know which other holes with threads you're referring to, but if you can adjust the mount to fit them, those might be the appropriate screw holes.
I have a 32 inch Samsung LNS3251DX/XXA Version AM03 flat panel television. I want to mount the tv and bought the according VESA mount however the top two holes on the back of the tv, used to attach the mount to the back of the tv, the threads for screws have fallen out of the holes. This leaves only the two holes with threads for screws in the middle of the back of the television. Is it safe to just mount the tv using just those screws if the tv is not going to be moved much? If not, is it possible to use any of the other holes with threads in them to mount the tv? Thank you for your time