OK I figured out how to fix this. I was using the default Ubuntu 10.10 nvidia-current
drivers. I read that other people were having problems with these drivers, and recommend using the direct Nvidia installer. The next best thing was to try the drivers in the X-Updates PPA.
Solution: Upgrade nvidia driver from the 10.10 maverick repo to the X-Updates PPA versions
Run the following commands or directly edit /etc/apt/sources.list
apt-add-repository 'http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu maverick main'
After this I rebooted. The very first time with the new drivers, the video froze after 5 sec, but since then it has been working fine. The first lock up might have been my HD signal. Hope this helps someone in the future.
Some detailed info here: http://readlist.com/lists/mythtv.org...35/177930.html