The exact text of the iMac's error:
"""
Device does not support 1x32 FP render target format.
RaiseException() Address = 0x7b82e18b (filename not found) [ in C:\windows\system32\KERNEL32.dll]
Address = 0x7857dbf9 (filename not found) [in C:\windows\winsxs\x86_Microsoft.VC90.CRT_1fc8b3b9a1e18e3b_9.0.30729.1_x-ww_6f74963w\MSVCR90.dll]
DDRESS = 0X5EBDE8 (filename not found) [in C:\Program Files\2k Games\Gearbox Software\Borderlands\binaries\Borderlands.exe]
Adress = 0x8785ad2 (filename not found)
"""
This error may actually be a problem with this game and this series of ati cards, since I have read of other problems for windows users elsewhere on the internet. Or this could be another problem with the apple/ati drivers. I also may not be meeting the system requirements, but I though this card was ok.
I would say the laptop's issue is the more important of my two problems however.