This bug has been copied from bug #541953 and has been proposed
to be backported to 5.4 z-stream (EUS).
We were able to trigger the issue on a Dinar with the RC1 kernel and a script similar to the one posted in comment #30 of Red Hat bug #541953. It took only a couple of seconds to take the box down. After installing and booting into the RC2 kernel (2.6.18-164.9.1.el5) we ran the script again. The box survived 2 hours of random CPU hotplug. It's safe to assume that this fixed the problem.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.