Problem changing desktop background

[davy jones]

im unable to change my desktop background in ubuntu 9.04. i was able to in the beginning but now all of a sudden its not happening. nothing happens when i right click on my desktop. when i go to system->preferences->appearance n select a background i want it doesnt change. please help me out

[gettinoriginal]

First, try this, it may not work, but it won't hurt.
Alt F2 and type
gconf-editor then choose run.
When window opens, then Apps > Nautilus > Preferences > show desktop should be checked, exit and reboot.