I had been sharing my desktop with a colleague, with the feature to disable the background wallpaper while connected. We had some problems with the connection and my Desktop Sharing program became unresponsive so I killed its running process (with SIGTERM).

No, regardless of whether I have desktop sharing enabled, my desktop wallpaper is not displayed. I have tried rebooting my machine, (making sure that desktop sharing isn't started in my default session) but although the wallpaper is briefly display, as soon as my panels are being drawn, the wallpaper disappears and all I can see is the solid background colour. Changing desktop wallpapers does not fix the problem - the solid colour sometimes changes (depending on the wallpaper's settings), but the actual picture is not displayed.

Any ideas how I can fix this?

(Using Ubuntu 8.10).