Thanks Ket
I have relayed this onto nVidia (and credited you for your expertise and knowledge).

Indeed STEvil, I must admit I was concerned when I saw 102C and informed Mike that his GTX 480 was running extremely toasty. For comparisons sake a GTX 295 (Single PCB) in my system runs upto 86-88C after one whole hour of Furmark @ 1920*1200 16XFSAA. I think that is "safe" as during heavy gaming the card never goes over 70C (according to eVGA precision tool).

You are right, I think the DX58BSO had this issue fixed in a BIOS update.

Fixed issue where SMBIOS System Slot structures mismatch for PCIe Express Gen2 slots
Listed as a fix for July 2009?

Also in May 2009
Set Slot Power to 300W for PCI Express x16 slot
But then again I know nothing
John