in my case it was: external: 1920x1080 internal: 1280x800 Exactly the same issue as f1anker described.
Unfortunately won't be able to test a lower resolution until October. I am attaching lspci output, hope this helps. ** Attachment added: "lspci" https://bugs.launchpad.net/unity/+bug/808677/+attachment/2434573/+files/lspci -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/808677 Title: Failed to activate external monitor (dual monitor mode) To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/808677/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
