I use geforce 9500m with nvidia 256.44 drivers on 64-bit ubuntu 10.10.
The system is very sluggish and unresponsive comparing to prior experience with ubuntu 10.04, which used libcairo2 1.8. Compiz animations stutter and window contents are being drawn slowly. Moreover, there are elements the system fails to paint correctly with the nvdia driver:
1. Selected menu items and progress bars are brighter then they should be.
2. The lovely glowing dots below docky icons, which mark which app is being ran, become large, ugly grey blobs.
The issues disappear if I downgrade libcairo to the 1.8 branch.
Screenshots are found in the ubuntu bug report (https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/612614). This bug has links to many reports of people who suffer from similar issues.
That is a bug with the nvidia binary driver's rendering of gradients. See https://bugs.launchpad.net/murrine/+bug/605979/comments/13 for a more detailed discussion of the problem.