Studio Display freaks out when I use millions of colors

Hi,

I have a 17" Apple Studio Display (LCD). It's currently running great on Thousands of colors. However, I recently realized it was running on "thousands" and not "millions", so I naturally switched it over in the Display Settings. Unfortunately, I am met with awful black boxes, lack of refreshing, lines, etc. basically VERY little response by the LCD.

For instance, when I hover over the dock, it freaks out - the icons all flash black. Some folders on the desktop are completely black until I click on them, when they "appear" in color. Switching windows causes all kinds of refresh problems.

When I go back to "thousands", the problem doesn't go away until I restart.

A couple other details:
- problem is replicable no matter the resolution settings
- I've tried zapping PRAM, updating NVIDIA drivers, fixing disk permissions, etc.

Am I missing something obvious? Any ideas? Please help - I'm at a loss! Normally thousands of colors would be great for me, but since Quartz Extreme requires Millions, I can't experience all the great new visual features of Safari 4.

Thanks for your help,
Tim