I have an HD4890 and i can not run the test in full screen, native resolution shader complexity = 3 without error check.
I must underclock gpu @ 700 or underclock ram. If not, i have a black screen in 1sec and i must hard reset the computer. (security of the card because of the amp higher than 82-83A)

If this was the case when you run a cpu not overclocked with IBT would you think it is normal?

I think a card design should handle 100% charge even if no game is (not yet) doing it.