iMac White (Late 2006) Problem with X1600 graphics card

Hello,

I have the ATI X1600 graphics card in my 20" iMac. I recently installed Tiger Woods 08. When I go to play the game it tells me that I do not have a supported video card. When I checked in system profile it says:

ATI Radeon X1600:

Chipset Model: ATY,RadeonX1600
Type: Display
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 128 MB
Vendor: ATI (0x1002)
Device ID: 0x71c5
Revision ID: 0x0000
ROM Revision: 113-xxxxxx-139
EFI Driver Version: 01.00.139
Displays:
iMac:
Display Type: LCD
Resolution: 1680 x 1050
Depth: 32-bit Color
Built-In: Yes
Core Image: Hardware Accelerated
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Supported
Display Connector:
Status: No display connected

How can I fix this problem? It my video card not enough to run this game? Also could the problem be that the chipset model is ATY,RadeonX1600 and NOT ATI? How to fix this?

Thanks