ati radeon 9600

[zoki bajatovski]

my ati radeon 9600 not recognized correctly 1024x768 is ok but refresh rate is not 85hz, how can i solve this isue? mac osx ver. ideneb 10.5.8

Here is my specs:
----------------------
ga8ipe-1000 rev 1.0
Processor Name: Intel® Celeron® CPU
Processor Speed: 2 GHz
Memory: 1 GB
Type: Display
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 256 MB
Vendor: ATI (0x1002)
Device ID: 0x4150
Revision ID: 0x0000
Displays:
SwitchResX4 - q770:
Resolution: 1024 x 768
Depth: 32-Bit Color
Core Image: Software
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Not Supported
QuartzGL: Supported