One more quirk that may need to be fixed:
I've been using dual monitors for just more than a year and I'm beginning to notice fade. Monitors create a magnetic field. When using dual monitors, I put them close together. Along the edge closest to the other monitor, the picture is "curling back" and "fading" on one of the monitors. The effect is similar to holding a magnet close to the display - only it occurs along the straight edge.
I believe the fix is to separate the monitors by an inch or so. The effect dissapated with separation but I don't know if it's a fix or just temporary.