Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 964796, so it is being marked as such. That bug was fixed with mutter 3.4.1-0ubuntu1. Any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.
Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 964796, so it is being marked as such. That bug was fixed with mutter 3.4.1-0ubuntu1. Any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.