hi. i've been playing around with premiere for a while now but i've just run into this problem. when i try to preview the timeline in the monitor everything is VERY choppy without audio. i get about 1 frame every 3 seconds. this was never like this before... did i change settings? the files are fine (i can see them real time in windows media player) i can even use the scrubber and see things in real time... preview just doesn't work. any ideas?