I’m using a 6x8 Intuos3 and am having the following problems:
Flash 8: lines are choppy even when smoothing is turned to 100%. I wasn’t experiencing this on Win XP, but now I do on Win Vista. This problem even occurs when I’m using the mouse, so it’s probably not a Wacom-specific problem.
Illustrator CS2: brushes are much smoother but always start with a single click. I experience it both in Vista and XP.