Same issue here as reported above, both on Xubuntu 14.04 LTS 64 bit live USB and fully installed desktop, and also Ubuntu 14.04 LTS 64 bit live USB, running on custom MSI A55m-E33 with AMD A6 and 2x4GB DDR 1600.
Fortunately adding "radeon.dpm=0" to GRUB command line seems to have solved the rebooting issue on Xubuntu 14.04 64 bit installed on pc, with latest stable kernel 3.14.4. Have not tested the live USB versions. It might be noteworthy that I also have Lubuntu 14.04 32 bit installed on a separate drive and it runs flawlessly - I've had many issues with Xubuntu and graphics in the past, but for some reason Lubuntu never complains. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1309578 Title: Ubuntu 14.04 suddenly reboots when booting from Live USB AMD A8 6600k To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1309578/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs