First a big thank you for the new Alpha! It's becoming very usable. 
I just noticed a rendering bug with the settings window, seems not to affect the other windows that I have opened. When I flick scroll up and down the (child) window, the display becomes corrupted. First the text becomes slightly blurred, then it goes haywire:
I wonder if anyone is seeing the same?
My config: iMac 2.8GHz Intel Core i7 / 8GB 1067 MHz DDR3 (4GB given to Parallels), 2TB HDD (500GB given to Parallels), ATI Radeon HD 4850, Mac OSX 10.6.2