I had the same problem. Some research turned up that you need to disable "Workaround transcode NPTL bugs" in Miscellaneous options under Preferences. This option should be off by default on amd64 systems, so this bug should not be closed until that is fixed.
-- Dependancies installed, but not recognised https://launchpad.net/bugs/33312 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs