I'm having the same problem with BAMT 1.2 as well as SMOS and NotSMOS.  For BAMT 1.2 I even tried applying the newest drivers and recompiling cgminer, didn't help.  Not sure where the problem lies, but you're not alone.

SMOS had it's own issues with freezing, and the Cards would appear and disappear from the status.pl web interface thing, just like in GPUMON.