I'm having some problems with my Gigabyte 5970 card. The card is running at stock clock settings (also with underclocked memory). Catalyst 11.5 drivers. GUIminer with "-v -w 128 -f 10" settings.

When I start mining with that system, it runs for anything between 10 minutes and ~24 hours before crashing/rebooting for no reason at all, typically falling in the 8-12 hour range. I have been trying to monitor the temperature of the cores, and they appear to be within the normal operating range for this kind of card. No higher than 85C now that I'm running it as a stand alone card.

Anyone have any insight as to what might be wrong? Is my card broken, or can this be worked around?