I followed the instructions at:

The install worked fine and the xorg log file looks OK when X starts - using fglrx, DRI, etc.

But screen updates are so S-L-O-W that It's unusable! Scrolling in a window slowly redraws again and again - same with moving windows. The vesa driver is much more usable.

fglrx_info hangs the machine - hard - have to power cycle!

The card is an AGP Radeon 2600 XT running Fedora 8 with all updates.