GUI Miner & BTC Guild works for short time

[i3one21]

I have three 7950's that will run 24/7 on Bitminter using GUIMiner.

When I setup GUIMiner to connect to BTCGuild, the three cards will work for 10 - 30 mins and then the hash rate drops to like 1.5Mhash/s - 600 khask/s.  It will continue to mine that slow.  Any ideas the reason for the crash?  I'm not using any extra flags on bitminter or when I try BTCGuild.  I have tried some flags when connecting to BTCGuild because it kept crashing, but didn't stop it from crashing. 

I am also on 12.8 AMD drivers.  It crashed using the latest and 13.1.

I want to be able to mine on BTC Guild.  Suggestions?