Smooth: No one knows. Blizzard Tech Support just tells people to lower settings and get new drivers, but this is something that cropped up two patches ago. Add to the framerate drop suffered by most audigy users thanks to the new proprietary WoW sound setup.
I just wish the people on the tech forum would realize that prior to two patches ago we were all doing fine. I think its primarily the GeForce 8 crowd, as my 7800 was fine.