Display corrupts after a while

This has been detected on Utopic, Vivid and Wily and on two different machines.

Basically, you can login fine, with a background screen and everything correct. But, after a while (and there is no consistency behind what/when/why), the background will reset to the default Ubuntu background, and the desktop icons will suddenly randomly start overlapping. Rebooting fixes this temporarily.

Functionality, everything works fine, other than this graphical error.

Example of the overlap attached.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: cinnamon 2.6.13-1ubuntu2
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
CurrentDesktop: X-Cinnamon
Date: Thu Oct 29 18:21:06 2015
InstallationDate: Installed on 2015-10-18 (11 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20151017)
SourcePackage: cinnamon
UpgradeStatus: No upgrade log present (probably fresh install)