Nvidia driver causing Xorg to crash at boot time

[Joe]

Recently I've got a problem with the official Nvidia driver. I used to run it on Ubuntu 10.11 and older versions and it never gave me any serious problems, whatsoever. Then one day, it stopped working (Ubuntu 10.11). By stopped working I mean, Ubuntu could not load, it hangs in the middle of the loading process and keyboard does not respond: i.e. if you press the Num Lock button it does not change its state. But the kernel keeps running, i.e. you can communicate to the O/S via SSH. Also the system does not hang if you boot in text mode (using the "text" option at Grub).

I thought Ubuntu got somehow corrupted. So I've installed the latest version, that is 12.04 (fresh installation). Then I've installed the current Nvidia driver using Ubuntu's Additional Drivers option, rebooted the system and it again hanged. Then, I've booted in text mode removed the Nvidia driver, and installed the latest Nvidia driver by adding a PPA repository.

For weeks everything worked well until a few days ago. That day, I've tried to boot my computer and it again hanged. Tried to remove the driver and replace it by another one from another PPA repository, and no luck. I've even tried to manually install Nvidia driver (that is provided from Nvidia.com) and it did not work as well.

Also I've tried to blacklist the nouveau driver, but the system still crashed.

Side effects:
* Keyboard do not respond, giving the illusion that the kernel has crashed
* You can only communicate with the O/S via SSH
* You can't terminate the X server (sudo kill -9 <xserver_pid>)
* You can't reboot/poweroff the system (sudo poweroff or sudo reboot)

Hardware / Software info:
*-display
       description: VGA compatible controller
       product: GF110 [GeForce GTX 560 Ti]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:16 memory:f6000000-f7ffffff memory:e0000000-e7ffffff memory:ec000000-efffffff ioport:ef00(size=128) memory:e8000000-e807ffff

Distributor ID: Ubuntu
Description: Ubuntu 12.04 LTS
Release: 12.04
Codename: precise

Linux melitas 3.2.0-24-generic #37-Ubuntu SMP Wed Apr 25 08:43:22 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
ii nvidia-common 1:0.2.44 Find obsolete NVIDIA drivers
ii nvidia-current 295.53-0ubuntu1 NVIDIA binary Xorg driver, kernel module and VDPAU library
ii nvidia-settings 295.33-0ubuntu1 Tool of configuring the NVIDIA graphics driver

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The crash dump (logged in dmesg) can be found in the attachment named dmesg.txt