Hello,

Try other resolutions such as 1280x1024 or 1600x1400.
They both work for me with an ATI x1200

I have not yet find a kext to get QE
At the moment I have not used any video kext or anything for RS690.

Display:

Type: Display
Bus: PCI
VRAM (Total): 256 MB
Vendor: ATI (0x1002)
Device ID: 0x791e
Revision ID: 0x0000
Kernel Extension Info: No Kext Loaded
Displays:
Display:
Resolution: 1280 x 1024
Depth: 32-bit Color
Core Image: Software
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Not Supported
QuartzGL: Supported