dual boot 8.10 and 9.04 and dual monitor setup - gnome panel positions

[Colin Law]

Hi

I have a dual boot Ubuntu 8.10 and 9.04 setup with a common /home
partition.  I have a Toshiba Satellite laptop with an external monitor
which I use in conjunction with the laptop display in extended desktop
mode.  This works fine except for a problem with the gnome panel
positions at the top and bottom of the screen.  I can set which
monitor I wish these to appear on using gconf-editor and setting
/apps/panel/toplevels/top_panel_screen0/monitor (and
bottom_panel_screen0) to 0 or 1.  The problem is that on my 8.10 boot
monitor 0 is the external monitor and on 9.04 monitor 0 is the laptop
display.  I am at a bit of a loss to know why or what to do about it.

I have checked the two xorg.conf files and they are identical (default
except for the virtual display size to encompass the two monitors).

Any suggestions would be much appreciated.

Colin