Are you sure it just works on the left screen?
When we tried dual monitors I found the board will display the right hand screen (which we had through a splitter to the monitor and projector), but the pen would actually track across both monitors.
So when we had the pen on the far left of it's projection area it was on the far left of the left hand monitor, when it was in the middle of the screen it was either on the right of the left hand monitor or left of the right hand monitor. By the time you got it to the far right of it's display area it was on the far right of the right hand monitor (the one time it actually mapped with where it was projecting the cursor).
The Easy Interactive Tools seemed to imply you could tell it which screen to extend over, but the pen mapping always went across both monitors not matter how you set it in the Tools.
I couldn't find a Easy Interactive Driver Calibration option, only on the projector itself which was no use.