Pro tools, Video randomly stops playing

[Frontman Music]

Hi,

I have a problem whereby the video window plays back for a while when tracking audio for film.

Then randonly it stops working - the video track in the arrange window shows the frames, but the video window will not play back. The session then wont's even start video of any sort whether you remove the video import and even import another video.

I then have to take a completely new video file from my client, creat a new session and import the individual video tracks one by one. This then runs for a while and then the whole process repeats.

I don't know what the issue is as the issue has remained through PT7 LE right through to now when I am on Accel1, with HD PT 8, 96 io.

The machine is stable, running PT only Win XP service pack 3. I have qtime 7 installed.

I am copletely stumped, anyone?

J