Some multi-monitor setups use negative numbers for one of the monitors. With Nvidia drivers 6.14.10.6693 I attempted to reproduce this behavior but I was unsucessful, The screen coordinates were always positive. I'm not sure if this is something changed from earlier nvidia drivers or just my setup.
Could you please run the mult-monitor test program attached to this post and report your results. I hope to use this info to improve FlashFXP multi-monitor support.
If you're reading this read and you have a multi-monitor setup, even if you currently don't have any problems can you please post your results. Thank You