hmm...strange. i think i can recall getting that a few times but not as bad. are you by any chance moving an objects vertices, and then select a different object and maybe play with that a little bit and then going back to the original object? that MIGHT be whats happening (or might not be).   I would try just saving the scene, starting a new scene then going back into it--or try saving your scene then exiting maya, then opening your scene again.....maybe reinstall?

hope this helps, good luck