I have a setup at work where my external 19" monitor sits to the left of my laptop (actually eeepc 1000h) running slack 13.0 with KDE 4.2.4. I've set this up successfully (see this
thread) and am happy with it.
At home my arrangement is that my external monitor is above my laptop's screen. This is a simple change to my work arrangement (either via xorg.conf or xrandr as I don't hit the 2048 limit vertically) and seems to work OK at first, but it's currently unusable because windows cannot be dragged from the upper screen to the lower screen. If I try, the majority of the lower part of the window will smoothly appear on the lower screen during the drag, but then the drag gets stuck (i.e. the mouse pointer & window don't move down as I move the mouse down) when the menu bar of the window reaches the bottom of the upper screen.
It seems like a KDE issue and I dimly recall hitting something similar with KDE3 in slack 12.1, so I'm not going to blame KDE4 just yet
Any ideas?