Please describe the problem:
Plenty of linux apps recognise that I have two screens and place themselves
accordingly on either screen, or avoid displaying across the centre.
gnome-background-properties just assumes I have a 2048x768 screen, somehow, and 
a) lacks an option to select an individual image per screen
b) lacks the ability to smartly tile images around more than one screen (or
resize wallpaper images > 1024 and then tile it)
c) is generally less-than-perfect

Steps to reproduce:
1. Set up Xinerama.
2. Curse because it's a bitch and some apps don't work and you had to edit
xorg.conf manually
3. Download a really cool 1280x960 wallpaper off the internet
4. Watch in despair how the only way to get it to display without opening gimp
and editing it is to have it cut across the centre of the screens.
5. Avoid the niceness it is to have two different wallpapers on two different
screens because it's too inconvenient to edit files for that purpose alone.


Actual results:
You become slightly frustrated and either forget about it or learn to stop caring.

Expected results:
You aren't aware of any problem. It took you three clicks to set the wallpaper.
All is good.

Does this happen every time?
More or less, now that 1024x768 res' are on the lower end of computing and
artists supply images for larger screens.

Other information:
Make a tab per screen, or some other UI trickery that doesn't appear when you
only have 1 screen. 90% of your userbase won't notice anything changed. The
remainder of us will probably appreciate the extra abilities.