Thank you for your reply. As the cause of the issue was never confirmed I'll close this by marking "Invalid".
** Changed in: firefox (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1512964 Title: overlapping frames displaying new tab To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1512964/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs