The wallpaper of my desktop doesn't appear and instead only the wallpaper of my login screen appears in my desktop. Also though the launcher, panel everything appears(as shown in the screen shot) they work as well. I tweaked my settings with ubuntu-tweak and everything went haywire after that. I have even deleted ubuntu-tweak after that yet the issue persists.

I've read this article on UbuntuForums but still don't understand.

Someone please explain it to me.

here's the screen shot from my desktop, http://goo.gl/L8sQly
(sorry i can't post image here, because my reputation is to low)