Specifying the primary monitor with xrandr, xfce4 and xserver-xorg-video-intel

[Andrew Robinson]

Is there any way to tell XFCE which monitor to treat as the primary one?

I am using the intel graphics driver, and am positioning my monitor
using xrandr's 1.2 features:

#enable external display
xrandr --output TMDS --auto
# set location
xrandr --output TMDS-1 --above LVDS

all my applications go to the TMDS-1 (External DVI monitor) and not to
the LVDS. Even worse, when I disconnect my external monitor, all the
open widows shift down and I am left with the title bars only showing
just above my panel at the bottom of my laptop.

I would like my laptop to be the primary monitor. Is there any way to
do this with XFCE?

Thanks,
Andrew