Running latest mythtv-0.23-fixes from svn, built from source locally on the same machine. Base system underneath originally came from Mythbuntu-Intrepid, but a few packages have been upgraded since then.
The USB display app, which used to
query the GPU temperature, is available from my web site at http://rtr.ca/vfd_updater/
The temperature probe can be re-enabled by an "#if 1" on line 846 of vfd_updater.c