In most cases he should, but it depends on the oem/bios. Also, if you have a secondary card in the pcie x16 slot, it will disable the DP port since they share lanes. There really should be a bios option to enable/disable the DP port.
The monitor is a single link. In fact, my DVI wires themselves are only single link (missing the 6 pins in the middle) and work when plugged into the DVI port, so definitely shouldn't be needing any active adapter.
I have no cards at all in any of the slots, and there's nothing in the bios to enable the DP. I have looked at those "dual slot" and "internal graphics mode" options, the "internal graphics" option is enable/disable and whether or not to use sideport memory. I don't think that sideport should make any difference to it, but I guess I might as well try just to make sure.
BTW: sorry it took me a while to get back to this, car window spontaneously self destructed yesterday, had to replace it.
I'm just about to go through all the bios options again in every possible combination. I've also readied the W7 to test -- if it also fails there, then at least I can conclude that it is either a bios configuration, bios bug, or defective board.