Seems to be an 3D rendering problem of the radeon driver since it affects Mint(Debian Edition as well as Ubuntu based) Cinnamon too.
** Also affects: debian Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to mesa in Ubuntu. https://bugs.launchpad.net/bugs/751828 Title: Corrupt (stripes) panel shadow texture To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/751828/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp