no desktop

[Simon]

When I came onto the computer this morning I found that gnome-panel was 
taking 99% cpu for no apparent reason. I rebooted and the system went 
down and back up successfully. When I log in though, everything loads 
apart from the desktop. It stays the default blue colour instead of 
loading my background image, no icons are displayed, and I cant interact 
with it by right clicking (nothing happens). Im a bit stumped really as 
I cant find any error messages anywhere.