VLC and Movie Player both crash

Hi all,

I had a fairly clean install of 7.10 and both VLC and Movie Player were working fine. I did a few things, including installing wine and utorrent and when I rebooted neither VLC or Movie Player would work. A second reboot and everything was working fine. There have also been some other screen related glitches (screen saver hangs for example, or whole screen goes blank for a second and then redraws). Now both apps have started crashing again.

I had been using the ati proprietary driver but tried switching back to the open source - no difference.
This sounded like a similar problem reported back in January so I tried that fix (downgrading X and then upgrading) - no difference.
Removed and reinstalled VLC - no difference.

When I run it from a console the messages I get from VLC are:
VLC media player 0.8.6c Janus
X Error of failed request: BadValue (integer parameter out of range for operation)
  Major opcode of failed request: 141 (XVideo)
  Minor opcode of failed request: 19 ()
  Value in failed request: 0x3c00006
  Serial number of failed request: 85
  Current serial number in output stream: 86

Which is beyond my ability to interpret. The display adapter is the motherboard builtin graphics - ATI/AMD 690

The only other things I can think to add are that 1) sometimes when VLC crashes the entire screen gets a green then pink cast to it for a second or two and then returns to normal. And 2) sometimes instead of just crashing Movie Player seems to think it is playing the movie although the screen stays black.

In summary: reinstalled (downgraded then upgraded) X, reinstalled ATI proprietary driver, removed and reinstalled VLC, changed from proprietary driver to open source driver... none of which helped.