If a desktop has two DVI ports on it, it may randomize which of the two ports it decides to broadcast the signal out of.

This sort of pain point fits with the challenging day I've been having. I have a sore throat, there was a fire at the hotel, and it snowed heavily...

Update: The fire turned out to be a prank. Someone sprayed a fire extinguisher all over the fourth floor and then pulled the fire alarm. I was fooled!