I'v bumped into a little problem while running AHK.

I run two WoW-windows on on computer, running them on two different monitors at the moment (I'v tried using only one minitor aswell, but I guess this is irrelevant).
I'd like to have both WoW-windows up at the same time since it makes it alot easier to pick up questloot, accept quests etc.

It works fine and runs smoothly when I have the game minimzed.
But when I have both windows up, my secondary character gets logged out after ~20 seconds of playing, anyone else that have experienced this?