flv freezing randomly!!!!!!

Hi all,

I am using a one of the video components from flash to play an flv but once I upload it, it seems to freeze in the middle of playing. I've tried compressing it again and again in the Flash Video Encoder. But, to no avail. Does anyone have any suggestions? I'm desperate. I've tried it as Sorenson Spark, as well as the on2 VP6. And I keep playing with the video data rate, lowering it or increasing it. The original files are in the 400mb range, but once they are compressed, the are around 6mb. Any ideas?