For what it's worth, I'm having the exact same problem, but using crunchbang, not ubuntu. I have an AMD Athlon II Neo K325 processor, and I've had the same problem with crunchbang waldorf and statler (based on debian wheezy and squeezy).
I've isolated the problem with my current setup (64-bit waldorf) -- it only shows up after a reboot if the computer was put to sleep at sometime during the previous session. So: Power up, do stuff, power down, power up -- no problem. Power up, do stuff, sleep, wake, do more stuff, power down, power up -- problem The problem is just as described -- grub fails to load, just a solid cursor in the upper left corner, followed by a blinking cursor. A quick touch to the power button will make the computer power off, and ctrl- alt-delete will make the computer reboot. However, the problem won't be resolved unless I either pull the battery or boot into some live session. Pulling the battery has always fixed this for me. Very strange. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1081819 Title: (12.10) intermittent boot failure / black screen Status in “xorg” package in Ubuntu: New Bug description: Ubuntu 12.10 (Xubuntu) HP p2-1033w - AMD E-300 APU with Radeon 6310 integrated graphics My pc sometimes will not boot properly and will stay at a black screen with blinking cursor. It usually displays the GRUB bootloader and boots normally. After disconnecting and reconnecting power, I am able to boot Ubuntu but the intermittent booting problem continues. edit - log from boot-repair http://paste.ubuntu.com/1378561/ To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1081819/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
