hi i'm having trouble with playing avi. files(which have 3ivx D4 4.5.1 Pro Video Codec)on Sony Vegas 6. Everytime I open the file and play it on Vegas the video is all black and corrupted but the audio is fine. I thought my computer might be missing the codec but when I played the file on windows media player it was perfectly fine.So i think it's just the codec in the program that's missing or something. I've used Vegas before and it was working perfectly until i tried upgrading it to Vegas 8 PRO. Now both have the same problem and i don't know what's causing the problem. can someone please help?