I'm having same kind of problem where mouse clicks are not responding. Only way is to switch workspaces, but that doesn't always help.
Best solution so far has been right clicking on the zone where the mouse was when it stopped responding. This problem is more frequent all the time -- Mouse clicks stop working sporadically https://launchpad.net/bugs/41301 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
