OK it sounds like Mutter is calculating an incorrect display timing. I'm surprised the list of refresh rates is shorter because historically Xorg has had more.
** No longer affects: linux (Ubuntu) ** Changed in: mutter (Ubuntu) Status: Incomplete => New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2074559 Title: [nouveau][Samsung SyncMaster] Top margin of secondary monitor covered with black flickering rectangle To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2074559/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs