Gnutella Forums - Please help With My Video Duration issue

I have been having a lot of difficulty getting my movies to play for the correct amount of time. They all have varying ending times such as 5min all the way to 20min. But after the first minute is over the video stops and starts jumping images to the end of the video. Does anyone know if maybe this is a compression issue or something like that? is it a file reader I am missing? I can't figure it out, I have downloaded alot of file players but none of them seem to help it. Please if anyone can shed some light on this situation it will be greatly appreciated.