Matrox G550 fuzzy display on FC4 was fine on FC3

[Francis Beckett]

Hallo,

I run FC3 with a Matrox Millenium G550 video card, an AMD Athlon64 CPU
in an Asus K8N-E mainboard and so forth.

I've had no display problems with FC2 or FC3.

Being reasonably cautious, I installed FC4 in a separate partition.
During and after the installation the display was/is very fuzzy (out of
focus), when I open a window it isn't displayed at all, etc. etc.

The new and old /etc/X11/xorg.conf files are identical.

Kernel is version 2.6.11-1.1369.

The boot command in grub.conf is:
kernel /boot/vmlinuz-2.6.11-1.1369_FC4 ro root=LABEL=/1 rhgb quiet
initrd /boot/initrd-2.6.11-1.1369_FC4.img


Any idea what has changed between FC3 and FC4 (different video driver) ?
Any suggestions of kernel boot parameters which might help ?

Yours in hope,

Francis Beckett