When installing a fully virtualized guest, my host system spontenaously reboots. How can I prevent this from occuring?

Updated -

When using Red Hat Enterprise Linux 5.1 and a system with more than 8 logical processors, installing a fully virtualized guest may cause the host system to spontaneously reboot. This can be prevented by passing the kernel boot argument 'maxcpus=8' to the host system.

This issue will be resolved in Red Hat Enterprise Linux 5.2.