Having a strange issue with my rigs today.
Card clocks seem to randomly change, in both directions.
Each rig houses 3 5970s running at 725/250, I noticed to my clocks are jumping all over the board. I randomly have on GPU clocked at 820/300 on one rig and on another, 5 GPUs clocked to 725/1000 and the sixth at 750/250. I did not change these clocks and they have never been set to that.
sounds like you overclocked them too much... and your rig/bamt doesn't like it.
reduce your clocks, typically 800/300 works best for all my 5970's...
then try removing the noOCGPUx file:
: cdlive/image/BAMT/CONTROL/ACTIVE
: ls
(it will display the files needed to be removed, n then you follow by typing for each one)
: rm noOCGPUx
once done editing your .config, and removing each one of those files...
go back to gpumon, stop mining, start mining.
hope that helps, as it did for me from. (thanks to Spilrow for schoolin me on that :-) ).