Quick Tip for KDE 4.10 and Screens.
Today I had a rather annoying problem crop up. Every app I would launch would appear 99% off my monitor's display, leaving only a tiny slice of the side of the app window visible. I would have to grab and stretch the window so it extended to my display, where I could then move and re-size it where I wanted.
I found a simple solution to this. It was in KDE's new monitor controls. I have an old nvidia card (6600) that has a DVI and VGA connectors. It was listing one of them as a (TV) device, even though nothing is plugged in to it. For some reason my apps all decided to begin launching on the screen that didn't actually exist. The fix was simple. Go to System Settings > Display and Configuration > and then disable the unused screen.
Once I disabled the unused screen, KDE now only lists one active monitor, and apps are no longer launching on the wrong screen.
Hope this helps any single monitor users that might run in to this problem.