Xorg high cpu usage after upgrade to Fedora 11

[Fau <dalamenona gmail com>]

Greetings,
i've just upgraded my laptop from Fedora 10 to 11 using "preupgrade" script.
The upgrade went fine, no problems at all, but now there is the process Xorg
stucked at 20% of CPU and growing, the OS is really slow and even fluxbox
is not responsive, not to mention Firefox or Thunderbird.
I've got a SiS315 video adapter and up to Fedora 10 it always
worked. I'm seding in attachment my /var/log/Xorg.0.log and /etc/X11/xorg.conf
Thank you in andvance for any help,
best regards,
-
Fabio

Attachment: Xorg.0.log
Description: Binary data

Attachment: xorg.conf
Description: Binary data