Desktop wallpaper won't display images, only colours and gradients

On my ubuntu 10.10 laptop, I've recently noticed (I'm a busy guy and don't focus on my minimalist wallpaper) that my wallpaper has disappeared and been replaced with a coloured background - annoyingly similar to the image I had before, which means I have no idea when it changed.

I've tried different image types, sizes, and filesizes, but I can't get any images to load - not even the defaults. I also have no idea how to debug this. Any help would be much obliged!

Solution 1:

Are you using compiz with the compiz-wallpaper option activated? If so, the default wallpaper dialog in appearance-properties has no effect since would be overrided by compiz. Check it in ccsm and if is enabled, disable it.