Comment 6 for bug 1001712

keepitsimpleengr, we are working on an nvidia-specific bug (today!) that causes various windows (including desktop sometimes) to be blank white. I expect that fix will arrive in compiz 0.9.7.10 for precise, or maybe even sooner in 1:0.9.7.8-0ubuntu2 (maybe).
See bug 1002602 and bug 729979.

More generally, there have been known issues with upgrading customized compiz settings. I thought those bugs were fixed, but if you don't mind resetting your compiz settings then this worked for quite a few people:
    unity --reset
And then log out/in again.