@GrimReaperTaken yes this of the legs (and other body parts) disappearing also happens but is less annoying because at least is slow. Some of the video calls Shepard disappear and reappears so fast that is really hard to watch.
The framerate is an interesting possibility though I did tested with both Vsync on and off, I feel if that was all, with it on (which is how I play) would avoid the problem? Maybe?