the problem for me Gersen was the pcmcia on my laptop. What i did was boot into single user mode:
in grub press 'e' over linux
Select the kernel press 'e' again
type single at the end of this line and press enter
then 'b' for boot.
this got me into single user mode but of course my keyboard on my laptop wasn't reconigsed, neither was an external ps/2. I found a usb keyboard and typed
chkconfig pcmcia off
and rebooted and it worked.
I updated the kernel after that from 2.4.20 - 8 to 2.4.20 -20.9
and restarted the pcmcia, which worked, but then after a while i got the same problem

. So i just turned it off and left it off.
I had another problem with my ati radeon U1 on my laptop as well, but that's for another thread.
hope that helps mate.
had to use that