dx9.0a here, but I just installed 9.0b and haven't done any real testing.
30.82 lacks driver options with antialiasing and ansio filtering, and I'd rather run 1280x1024 with no AA than roll back to 30.82 and get AA but lose framerate and other features in other games.
There are only 2 issues I have with current nvidia drivers - first is the no AA problem (could be fixed with 9.0b, haven't tried it yet), and the second is that if AH is minimized and then the screen resolution changes while on the desktop, when I go back to AH I get a flashy stairstep blue corruption on the lower 1/3 or so of the screen. I only recently found a workaround that did not require rebooting to fix, after I isolated the original problem to the desktop resolution changing while AH is minimized. The corruption happens when any screensaver, utility, or even windows error occurs that changes resolution. My printer drivers cause a "fake" BSOD that I can safely ignore, but that BSOD resolution change also causes the corruption in AH. Exiting and restarting AH doesn't help, rebooting is needed to fix the corruption.
The workaround was to run another properly behaved 3D program with AH still running but minimized, then exit the other 3D program. The one I use is a D3D fishtank screensaver demo. I start it up, flip through a few screen resolutions, then exit the fishtank. AH graphics are back to normal after doing that. I'm not sure if this is a display init issue with AH only, windows messing with something, a DirectX/D3D, or driver issue. I get this glitch with most nvidia drivers, but I haven't traced it's actual beginning since I'm not too interested in rolling all the way back to the 30.xx series. It seems like more of a windows problem, but I'm not expert.
Sorry about the thread hijack... thought someone might benefit from my workaround if they'd seen the same problem when AH gets corrupted after an alt-tab. Now I can fix it without rebooting.