i noticed that problem when you go to another level and you hear the others walking and you walking, but the screen freeze and you dont see you moving.
it happenned to me somethimes(2 times) when i entered in a level, it was on graal 2001 server.
one was when i entered on market place.
PS: on enigma e never saw it, and when i disabled d3d it dont happen on graal 2001.