Know what? Right now I am in Ubuntu 8.04. Huray! ;))
The upgrade was pretty smooth without any problems except Compiz. But the issue had been settled. The problem was occurred because,
It seems AMD’s scripts to build an Ubuntu package for 7.10 include a diversion for /etc/xdg/compiz/compiz-manager so they can add fglrx to the list of supported drivers. The problem is that they don’t remove this diversion on upgrade/uninstall so when you upgrade to Ubuntu 8.04 the /etc/xdg/compiz/compiz-manager file will no longer exist and compiz will not start.
So what I did to fix the problem was, enter