Just for the record, in order to use three (or more) monitors from a single graphics card, you must enable Eyefinity.
Nope - eyefinity is about monitor grouping. I toogle my eyefinity display group for gaming, then disable it in windows.
With Eyefinity off, I have three separate usable screens (i.e., if I put something on the left screen and maximize it, it fills just that monitor)
With Eyefinity on, I have what windows thinks is one big screen across three monitors. The taskbar extends across all three, and if I put a window anywhere and maximize it, it fills all three. That's how the games work.
Eyefinity would also allow me to use two of the monitors in a group and retain one as separate, if I wanted.