whenever i have two or more quicktime videos running, only the video brought to front runs fluidly. the background ones run choppy. also, if i bring up a window of say, safari, or just finder, all the videos run choppy.

what is going on?

this is a brand new MBP 2.4ghz, 256mb vid ram

my older MB with considerbly weaker specs (2ghz 64mb vid ram) could run say 6 videos all fluidly at once.