OP here. Sorry I went off radar for a while. I tried the 20131223 daily build of Ubuntu 14.04 Trusty Tahr Desktop AMD64, and it still had the problem when I booted the live CD. My up to date install of Ubuntu 13.10 (fresh install of that version) was also still having the same problem.
Seeing the Andrew had good luck updating his BIOS, I looked for updates for my own board. My BIOS version was "685 A105 x64", built around October of 2011. The EVGA website listed this BIOS as version A05. The website offered version R22, released 3-13-2013, for download. I installed that (had to do it from my Windows boot), and noted that my BIOS now says it's version "685 0.22 x64" and was built "03/01/2013 14:51:21". After this, both the daily build of Ubuntu and my up to date install of Ubuntu 13.10 both run fine without any acpi flag sent to the kernel. It looks like updating my BIOS solved the bug. Should this bug ticket's status be changed to "Fix Released", since a good BIOS has been released for this board? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/973933 Title: Random Reboot if I Boot with ACPI On To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/973933/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
