I use dual monitors and I got that DX error when I was browsing the web on one monitor while the game was running on the other monitor. Has hHappened to me a few times actually. Also, the game reacts differently now when I do that. It used to just play in the background when I'd be doing something else like browsing but now the game minimizes to the taskbar instead. Seems like the old alt-tab crashes that used to happen.
