I'm guessing your problems are different, since on my computer it won't even begin to suspend. The screen doesn't even go blank. It just pops up a message saying suspend failed and if gnome-screensaver is running it locks the screen.
I'm starting to wonder if the problem is just in some setting that I tweaked at some point and don't remember doing. Is there really no good way to find out what's preventing the machine from suspending?
OK so I upgraded to the Hardy kernel and now suspend works. Compiz is giving me some problems now, but I think that's more related to the kernel update than fglrx.
What I did to upgrade:
1) Add the line: deb http://archive.ubuntu.com/ubuntu/ hardy main restricted universe multiverse
2) Go into synaptic, press reload
3) Install the updates for linux-generic, linux-header-generic, libc6, and gcc and all their dependencies
4) remove or comment out that line I added to /etc/apt/sources.list
EDIT: Apparently the reason suspend worked and compiz didn't (although it was working somewhat, which was strange) was that fglrx wasn't loaded successfully. Upon reinstalling it, I now get stuck at the blinking cursor on a black screen when trying to suspend and have to do a hard reboot. I was so excited to have working suspend before. At least now I'm at the same place as most other people and it's not just doing some random nothingness when I suspend.
Oh and also, my weird gnome-screensaver problem is still here. Every time I boot I have to kill gnome-screensaver, or else when I close the lid the screen won't come on again when I next open the lid.