I can confirm that the 8.12's fixed my fallout 3 issue.
I would have to alt+tab or restart the game to restore frame rates. Also, occasionally, the frame rate would be 1/2 of what it should be upon loading a game, then jump to 60 after a minute.
All gone now.
Silky smooth with both cores of my 4870X2 chugging along.
Well well WELL done ATI.
Oh, man, I hope these drivers fix this issue as well for me. My rates drop in half whenever I do an in game "wait" for any amount of time. I have to alt-tab out and back in and then they go back up. Not a huge deal but it can sometimes get annoying. I'll install these drivers when I get home and see if it makes a difference. Fingers crossed.