i had trouble interpreting your description of swapping your monitors to test the ports, so correct me if what i say is wrong.
you are running both monitors off of the dvi ports on the card, one on each. when you say adapters, do you mean the ports on the card, or are you using DVI-VGA adapters or something like that to the monitors?
if both your monitors are set to the correct inputs and only one port seems to be working you could try getting an adapter for the mini-hdmi i think is on that card. radioshack should have mini-hdmi to dvi adapters for like $25 and if it doesn't work, you can return it. i just did it with a minidisplayport to dvi adapter.