I think it is the same bug but symptoms are slighty not the same. But I don't know how to recognize this bug in the logs. I put in attachment the kern.log when the boot failed.
** Attachment added: "Fail.txt" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/727620/+attachment/2186877/+files/Fail.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/727620 Title: [Radeon HD 5650 and 5470] Kernel BUG during recovery boot and in normal boot (Hybrid graphics) To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/727620/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
