quicktime freezes

When a website is running a long (1 hour-40min) quicktime video in Safari (a secure website) the video will freeze at random times (typically about 20-30 mIn) into the video. The video can be restarted by closing the video, going back to safari and restarting the video (which restarts from time 0). The run point can then be advanced to just before the prior stall time and the video will then advance throught the prior stall point without difficulty until the next stall.

I've tried rebooting the Ipad and the router. I have had no problem with other IOS and Mac devices running off this router.

At this point I am out of ideas. Help!!

Thanks.