DL585 G2 kernel panics with "NMI received for unknown reason 20"

[Andy Williams_3]

Hi I'm having problems installing RH AS4 U3 on
a DL585 G2. During the initial boot from the OS CD1 i recieve the message

"NMI received for unknown reason 20"

And then it kernel panics. I have the advisory related to this problem :-

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c00781084&prodTypeId=15351&prodSeriesId=3219717

and have enabled the "Linux x86_64 HPET Option" but I still get the same problem.

This problem does NOT occur on AS4 U4. Unfortunately, I'm resticted to U3 for other compatability reasons.

I have applied FW update 7.70 but this makes no difference.

The server has :-
64Gb of memory
4G HBA HP FC1242SR 4Gb PCI-E
HP NC340T PCIe 4 port Gigabit NIC adapter
HP Smart Array P600 controller with 512 BBWC
HP Smart Array P400 controller

I have checked and each of these components are supported in this server.

Any ideas ?