XF86Config for Powermac G5

[Arrigo Benedetti]

I'm trying to configure the graphics settings on a dual Powermac G5 
running YDL 4.0 rc3.
I did the installation with the GUI, but after rebooting the X server 
did not start.
Then I ran Xautoconfig where at least I got the 640x480 resolution running.
When I try to change the resolution with the "Screen resize and rotate 
function" I get the hourglass
spinning and notyhing happens.
Could someone please send me a working XF86Config file for this machine?

Thanks
-Arrigo