This issue is affecting me too. I verified that this is the exact behavior I'm seeing with my iMac 11,1. This issue does not affect all model iMacs. Mine is a 27" late 2009 model.
Here is how to check the serial number to determine the model. On the bottom of your iMac stand, you'll find a label with the serial number printed on it, or from the Apple menu, choose About This Mac. Configure To Order (CTO) models are designated with an asterisk (*). Check the last three characters on the serial number: iMac (Mid 2010) DAS, DNM* iMac (21.5-inch, Mid 2010) DB7, DNN* iMac (21.5-inch, Mid 2010) DB6, DNP* iMac (27-inch, Mid 2010) DB5, DNR* iMac (27-inch, Mid 2010) iMac (Late 2009) 5PC, B9U, CY8* iMac (21.5-inch, Late 2009) 5PK*, B9S* iMac (21.5-inch, Late 2009) 5PE, 5PJ, CYB* iMac (27-inch, Late 2009) CYC*, 5PM*, 5RU* iMac (27-inch, Late 2009) -- Imac Radeon HD 4850 switch "Mini Display Port" output during install resulting black screen https://bugs.launchpad.net/bugs/597070 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
