I have Nvidia GEForce 6200 TC card and driver 304.51 if that is significant. Things were working fine under 12.04.
This is a 32-bit (Intel Core 2) system with 4Gb.
Here are the main issues:
1. Trying to move windows is very slow and jerky.
2. I cannot resize windows at all.
3. If the Unity Launcher is in auto-hide mode, it will never appear when I move the mouse to the left side of the screen.
I did try setting to defaults in ccsm. Did not help.
Possibly related: How do I bring up the "Additional/Restricted Drivers" screen in 12.10? There is no "indicator" for it in the top panel.