I had the same issue, it was caused by the bump-mapped transparecy, which I guess my graphics hardwre (Intel Atom/i915) can't handle.
Commenting out the background-bumpmap: line in /usr/share/cinnamon/theme/cinnamon.css worked around the problem. Paul -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org