How did you do the rollback?
I might want to try and see if using drivers from 10.5.2 or the Leopard Graphics Update works with the MacBook's Intel GMA X3100.
Coming from the hackintosh world I can tell you how to do this, but haven't actually done it yet other then messing with the hack trying to get my system to work... couple ways to do this, but this is how I would do it...WARNING!!! This could mess up your system, and I suggest backing up the files before replacing, or having a manually downloaded 10.5.3 update in case it doesn't work right. Also know how to boot your system in safe mode.
For NVIDIA, if you have already installed 10.5.3...
1. Download/install Pacifist located here
http://www.charlessoft.com/
2. Manually download the 10.5.2 update from apple here
http://www.apple.com/downloads/macosx/apple/macosx_updates/macosx1052comboupdate.html
3. Then mount the update and open pacifist, drag the mounted image to pacifist and then install everything with regards to geforce kexts/bundles and NVDAN*.kexts. They will be under /System/Library/Extensions. This will require admin password. May want to verify/repair permissions with Disk Utility after. reboot. (BTW, I suggest replacing them all, but the previous poster only mentions the geforce kexts so may not need to replace the NVDAN kexts).
For the x3100...
Follow the same outline but instead of the geforce and NVDAN files replace the following:
AppleIntelGMAX3100.kext
AppleIntelGMAX3100FB.kext
AppleIntelGMAX3100GA.plugin
AppleIntelGMAX3100GLDriver.bundle
AppleIntelGMAX3100VADriver.bundle
AppleIntelIntegratedFramebuffer.kext
If it doesn't work, reboot in safe mode and follow same outline but use 10.5.3 update and pacifist to put the 10.5.3 kexts back that you replaced.
I have not updated my MP to 10.5.3 yet because of this problem, but may try it shortly. My Macbook doesn't have Diablo II on it, but this would give me a reason to try it