We are also experiencing this issue across our fleet of T61 Thinkpads, Type 7659 12U
The initially reported problem has been that the machines sometime hang with a (serious) Windows error and after rebooting, the display is stuck at 640x480. The correct driver loads, the display properties (GUI) is functional, we are able to change the resolution with the slider but after hitting apply when the display comes back on, its still at 640x480
The machine does run standard vga 1024x768 32bit in Safe Mode, so this is not an issue with the panel itself.
These machines had no specific updates, and also this occurred on two machines where the user had no local admin rights.
We have tried the following.
Updating the system and video driver with Lenovo System Update, and also using the Intel provided driver.
Disabling everything but essential services from start up.
Running Chkdsk, SFC, Rebuilding the page file. Restoring the registry (from Retrospect)
Virus, malware, and various rootkit scans.
Occasional we have had a few of these machine where the problem was intermittently resolved after the Thinkpad was docked (off) and started, but the problem does return after it was rebooted.
So far the problem has not resurfaced on machines we have re-imaged, but we need a more efficient fix as we do not have capacity to re-image if the problem continues.