This is something that has driven me nuts in the past too. Seems like today's games are written in a very strange way.
I mean, isn't the human eye only capable of distinguishing around 20 something frames per second? As far as I know, movie films only have 24 frames per second, and nobody detects any laging in the motion!!
What gives?!?! how come you have to have a ridiculously high frame rate count in order for a game to be smooth? Given the human eye's limitations, I really don't think that it's a frame rate issue at all, it has to be something else