strange behavior of sdl applications on radeon cards

[Marat N.Afanasyev]

hello!

i have an ATI Radeon X800PRO (R420) JI (AGP) and after upgrade to 6.8.0 
version of driver and above any application that uses sdl to display 
graphics, e.g. qemu, openttd etc., regularly freezes video output with 
only mouse pointer is moving, then it works again, then it freezes again 
and again.

Can anyone tell me, what should i try to solve this? any required 
information will be provided, if needed

-- 
SY, Marat