RHEL4-U2 on Dell PowerEdge 6450 Hangs on Reboot

[Xue, Chongjie "Jack"]

I have RHEL4 AS (kernel-2.6.9-22.0.2.EL) installed on a Dell 6450 4-way
system with 4 GB of RAM.   
This system has been unable to properly reboot since the release of
RHEL3. With RHEL4 the system still does not reboot. 

Has anyone encountered this problem? What's the potential fix for it?

Thanks.

Jack C. Xue
University Computing Services
Marshall Univ
1 John Marshall Dr.
Huntington WV