Problems with kernel-2.6.26 and 2.6.27-0.x.rc2

[Joshua C.]

I have a strange problem with the 2.6.26 series kernel. 2.6.27-rc1
branch is ok but the same thing happens with 2.6.27.rc2 and the
following. 2.6.25 branch is ok.
I filed a bug report here https://bugzilla.redhat.com/show_bug.cgi?id=458901.

The kernel loads fine until showing "starting udev". then it just
stops and cannot continue. on the 2.6.26 branch i need to keep pressed
atleast one key for it to continue. Then it goes further and
everything freezes when no key is pressed.
2.6.27.rc1 was ok but the same thing showed in 2.6.27.rc2 onwards.
with the lastes kernel-2.6.27-0.287.rc4.git7.fc10 after "startig udev"
I get black and white stripps on my screen and only hardware reset
helps. This makes me think it is something connected with the kernel
modesetting and my radeon gpu. It could also be udev but it is fine
with 2.6.25 and if i keep at least one key pressed then 2.6.26 works
fine. in everycase dmesg shows nothing. What could it be? How can I
see where the problem is?