I am having the same problem (Couldn't find valid PLL dividers).
I run Acer TM4600 laptop with Ati Mobility X700,Xubuntu 9.04, kernel 2.6.28-18.
Tried all versions from 6.12.192 up to 6.13.0.
Attaching xorg log.
** Attachment added: Xorg.0.log.old
I have done a regression test, and the last release that works fine is 6.12.4.
From 6.12.191 up, xorg log produces the aforementioned PLL error.
But let me explain further:
I was trying to upgrade only because with X700 at full clock, this laptop's
fan is spinning almost all the time, even when
