Does it happen if you only have one monitor connected (or turned on)?
I am a bit surprised to see this:
(II) RADEON(0): Using hsync ranges from config file
(II) RADEON(0): Using vrefresh ranges from config file
since you don't have any ranges in your config file.
Can you please add
Option "ModeDebug" "true"
to the Device section of xorg.conf and restart X and attach the new log?
Does it happen if you only have one monitor connected (or turned on)?
I am a bit surprised to see this:
(II) RADEON(0): Using hsync ranges from config file
(II) RADEON(0): Using vrefresh ranges from config file
since you don't have any ranges in your config file.
Can you please add
Option "ModeDebug" "true"
to the Device section of xorg.conf and restart X and attach the new log?