Here's how I've got the drivers to work.
1 remove old drivers
first you need to remove the drivers downloaded from the ubuntu repository.
$ sudo apt-get remove xorg-driver-fglrx
2 Install the new driver
follow the procedure as described on point 2 at http://wiki.cchtml.com/index.php/Ubuntu_Gutsy_Installation_Guide
With this lease you can enable compiz but video playback, google-earth and all the applications which require an overlay start flickering and are unusable.
The system works perfectly with compiz disables :(
4 power management
With this release ati (amd) claims that the problems related to suspend and hibernate are solved.
I haven't tried it yet as I've managed to disable this features time ago (when the system tried to suspend hanged-up) and I don't want to retry right know to figure out if now is working (maybe on a fresh install of 8.04). If you think you can have an easy configuration guide (packages needed, and manual editing to /etc/... files feel free to contact me. If it works on my Asus notebook I'll add it on my blog.