Always do a clean install !
I have installed 9.10 on 3 different systems. All were clean installs. All worked flawlessly.
I am very happy with 9.10.
If you tried to do an upgrade instead of a clean install, that is a self-inflicted wound.
One system dual boots with XP, one with Vista, and my laptop triple boots with XP, Vista and Ubuntu.
Whenever you move to a new operating system, Windows, Ubuntu or anything else, ALWAYS do a clean install.