Thanks!
Using: -k phatk DEVICE=0 VECTORS BFI_INT FASTLOOP=false WORKSIZE=256 AGGRESSION=13 on a single 5830 and get 312MH/sec

What driver / os / sdk?
w7 ultimate 64bits
catalyst 11.5
sdk 2.2
it used to work fie ( 3 days ). then i started having these problem, i have a pc next to me with same softs and bat and it works just fine
to momentarily fix it i have to close it and open up again, it will run fine till i get the same problem (5-45mins)