Or nVidia's. That clock locking issue John_Again mentioned sounds a lot like the issue I had across multiple released nVidia drivers. At least these are beta AMD drivers.
Looks like AMD's meeting expectations again.
Edit: And, coincidentally, the clocks on my GTS 250 are now locked at its 2D speeds. nVidia never fixed the problem I've been happening, they just shifted it from affecting my primary GTX 570 to my secondary GTS 250. An improvement, but not a solution.