Hide Forgot
If there is a issue in the system and you restart the computer, After the restart gnome has a wired background looks like a tile of 4 images of a screen-shot of desktop before crash! This goes away when you change the background! The bug may be related to some other package
This would be some sort of driver bug or possibly hardware bug, but there's not really enough information here to proceed further.
The thing that makes me think this is not a hardware bug is the fact that what appears in background is similar to a screen-shot of desktop before crash. I feel like a caching problem! I am not very aware of these mechanisms in gnome, does it keep the background in a cache? I guess after applying tiling/resizing you may be saving the result somewhere, and somehow this is being corrupted.