I forgot to mention that I have also tried:
Enabling and disabling the built-in PXE Option ROM bia the BIOS setting
Enabling and disabling the BIOS option to prompt before downloading Option ROMs
Enabling and disabling Multi-processor support through the Bios option
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I thought of trying 8259 interrupts instead of APIC, but can't see where to control this in the BIOS. The Technical Reference Guide states:
"Interrupts may be processed in one of two modes (selctable through the F10 Setup utility):
- 8259 mode
- APIC mode"
The Technical Reference Guide is dated September 2008, whereas the latest BIOS came out in August 2011, so maybe that option has disappeared.
I am not clear what the "Multi-processor support" option in the Bios refers to, but I suspect it may allow the system to present only a single core to any operating system to deal with licencing issues. On the other hand, could it relate to the MultiProcessor Specification for x86: http://en.wikipedia.org/wiki/MultiProcessor_Specification ?
I have considered trying to downgrade my Bios version, but the release notes for my current (latest) Bios say that prior versions cannot be installed over it.