I put this in this section because the dual screen can feature two desktops, one desktop or a duplicate desktops, obviously, and I didn't know where else to put it. (Mint 9 Isadora)
It's really very frustrating - Everything is fine on one desktop. Great. When I plug the second screen on it goes MEGA SLOW. Mainly just the internet which confuses me, why not the whole system? but no, just the internet.
I don't suspect there will be any solutions so I just sort of want some closure to this truly bizarre fault.