Comment 1 for bug 802741

Puh... quite old report.
Unfortunately, I'm running into the exact same problem, too (Oneiric 64bits)

The system used to boot fine, but now it won't start the X server.
"cat /var/log/boot.log" says:

// ------------------------
fsck from util-linux 2.19.1
fsck from util-linux 2.19.1
/dev/sda1: clean, 262607/917504 files, 1635974/3668224 blocks
/dev/sda3: clean, 17985/3907584 files, 10370672/15624704 blocks
Skipping profile in /etc/apparmor.d/disable: usr.bin.firefox
 * Starting AppArmor profiles [ OK ]
 * Setting sensors limits [ OK ]
 * Starting System V runlevel compatibility [ OK ]
 * Starting CPU interrupts balancing daemon [ OK ]
 * Starting deferred execution scheduler [ OK ]
 * Starting regular background program processing daemon [ OK ]
 * Starting LightDM Display Manager [ OK ]
 * Starting ACPI daemon [ OK ]
 * Starting save kernel messages [ OK ]
 * Stopping save kernel messages [ OK ]
 * Starting disk temperature monitoring daemon hddtemp: [ OK ]
speech-dispatcher disabled; edit /etc/default/speech-dispatcher
Checking for running unattended-upgrades:
// ------------------------

And there it stays.

The computer itself however, is not frozen, I can manually start a graphical environment:
1) "Ctrl + Alt + F1" to get a shell and logon.
2) Execute "startx"

Any hints?