Screen resolution issue with GX620 after sysprep and mini-setup

We are incorporating new GX620's into our image and are having an issue with the display settings/screen resoluton reverting to 640x480 with 256 colors after mini-setup and the sysprep process finishes.

 

After mini-setup runs, all of the devices are installed correctly in the device manager with the correct drivers, but the screen resolution on the GX620 reverts to 640x480 with 256 colors instead of the 1024x768 with 16bit color display settings specified in the sysprep.inf file.  All of our other hardware models (GX260, GX240) work properly and sysprep sets their resolutions to 1024x768 with 16bit color after mini-setup.

 

We use Windows 2000 SP4 with all current security updates and the video card in the GX620 is an ATI X600 SE with 128MB memory.

 

We also tried discarding our image and installed plain Windows 2000 SP4 on the GX620. We sysprepped that machine with all of the GX620 audio, video, nic, and motherboard drivers in one folder.  We specified display settings of 1024x768 with 16bit color and a vertical refresh rate of 75Hz, supported by the Dell 1905FP monitor.  Again, after mini-setup and sysprep completes, the devices are all installed correctly in the device manager with the correct drivers, but the screen resolution is set to 640x480 with 256 colors.  We also attempted to use other resolution settings (1280x1024, 800x600) and other vertical refresh rates (60 Hz, none) in the sysprep.inf file but the resolution always reverts to 640x480.

 

Has anyone else experienced this issue with the GX620 and sysprepped images, or does anyone have any ideas how to resolve this issue?  Thank you.