I've gotten all my information about 10.4.6 from the MacFixit forums, where there are enough issues for me to steer clear of it for the time being. And I still think Painter should be working properly, even with 10.4.3. I find that many of my brushes fail to work as described in the manual. For instance, the blender brushes don't work at all (at first they only didn't work on the canvas. I understand that there has to be some color there to blend, and that you can't blend outside a selection. But when I take a blender to a layer, I might as well be rubbing my finger on the screen. I've taken to saving the file as a PSD, opening it in Photoshop and doing the blurring there, but that's obviously a ridiculous long term workaround. And I can't seem to get much use out of brushtracking. I've tried a brush or two from every category and with the exception of the pencils, I can't get the sensitivity of stroke that is indicated in the manual and the ads.

As for the Wacom driver, that could be an issue. I will check when I get home. I just bought the Intuos3 9x12 and installed it the first of April, but that doesn't guarantee that the driver on the CD was the latest. I will check and get back to you.