No, from what i can see in my tests, it is part related to temperature, part related to CPU (one 4890 is ok on one CPU, bugged on other), and who knows what.
I have cards with bugg on everything, cards bugged only on some HW used, cards bugged at some level of temp. HD 4850x2 whas bugged on water at 10c and became ok at -30c ==)))
S`hit cards from ATi, no surprise here.