server hangs after sp1

Hi,

I have 4 OES linux server, all of them are up-to-date with red-carpet.
They were stable release of OES linux, then recently upgraded to sp1
with rug.

When connecting by ssh, with an lum enabled account, it freezes.
with putty, i can only enter my username, and can't get the password prompt.
on the server console itself, can only login root.
when this happens, if i'm already log-in root at the server console, I
can't issue commands, like top, ps or w to see what is happening, it's
like if a process is consuming all cpu or i/o resources.!>!?!

the only way i found to make this back to normal is to reboot the
server, and even a ctrl-alt-delete doesn't work, linux is complety
knock-out.
this wasn't like this with the initial release.
i suspect the newest kernel....

Marc