drawing on root window with GDK using pixbufs + a few other questions

[James Curbo <hannibal adtrw org>]

Hi, I use Xinerama with two monitors and got fed up with having to 
create my own wallpapers that stretch across the whole virtual desktop 
(instead of two separate images loaded in each screen), so I decided to 
try my hand at GDK/X programming. 
I got the idea from a Windows utility called Ultramon that allows you 
to pick a wallpaper for each screen. I figured I could duplicate this 
behavior in X with GDK and by grabbing some information from the 
Xserver about the Xinerama config. My initial very rough attempt is 
here: (note, this is hard coded for two displays)

http://www.raspberryheaven.net/~hannibal/code/xwpset.c

I can successfully grab Xinerama information and seemingly read in two 
images fine, but nothing happens when I call gdk_draw_pixbuf. I'm 
totally stumped at this point, being pretty new to anything past basic 
GTK stuff. What am I doing wrong?

(doing all this on Debian unstable, btw)

Thanks,
James