I get this problem quite regularly while using the flash stream to watch the videos. The video just stops and the slider goes back to the start randomly. The annoying thing is you can't move the slider to different parts in the timeline so you have to watch it from the start again. Is this a prob on my end?
I'm on a Mac btw.
The issue is on your end but I will def take a look at the issue for you via screen sharing software (teamviewer) and get this fixed asap. Please PM me your Skype, MSN or AIM name and I will contact you.