I had been running Ubuntu v7.10 on my laptop, and Compiz was working fine. My graphics card isn't good enough to run the most advanced features, like desktop cube, but I was still able to do a lot.

I've now updated to Ubuntu v.8.04, and now, nothing works. In the appearance preferences, there is no longer an option to select a custom set of effects, and whenever I try to select anything other than none, it tells me that desktop effects could not be enabled. I tried just going into the compiz-config settings manager and changing things, but none of the changes made any difference at all. How can I make compiz work again?

The problem is solved, the solution is here:
http://yoonkit.blogspot.com/2008/04/...-on-heron.html