Laptop screen below external monitor

[Nick Hoffman]

Hi guys. Using a large virtual screen and xrandr, I've got an external
monitor configured above my laptop's screen. Here's how I'm
configured:
* Screen is 1680x1950
* DVI-0 is 1680x1050, positioned at 0x0
* LVDS is 1440x900, positioned at 0x1050.
http://pastie.org/810576

However, when I disable DVI-0, the position of LVDS moves from 0x1050
to 0x0 , and the screen shrinks to 1440x900 :
http://pastie.org/810579

It's easy to grow the screen back to 1680x1950:
http://pastie.org/810581

However, if I try to move LVDS down to 0x1050, it stays at 0x0 :
http://pastie.org/810585

How can I move LVDS down to position 0x1050 ?

I'm trying to do this because that's where my KDE panels are. At the
moment, when I disable DVI-0, my KDE panels are no longer visible.

Thanks!
Nick