"snow" on a Thinkpad T42 display & external monitor

I have been using a Thinkpad T42 for over a year and, more recently, have
been experiencing problems with the display adapter. For several weeks now,
I have been getting multi-colored "snow" that seems to propogate in columns
on the screen. These appear on both the laptop display and the attached LCD
monitor. Up until today, the "snow" usually resolves itself a few minutes
after startup, just by opening applications. Today, though, I am still
getting this, after 2 hours of the laptop being on. (If anyone wants to see
what I'm talking about, I have a JPG of a screenshot I can send privately.)

I have hesitated to contact our "help" desk as their solution for everything
that goes wrong on a pc is to reload the OS, and they do not have a
slipstreamed install image for our environment, and it will be two days
minimum to get my environment back to where it is now. So, my questions
are:

1) Has anyone experienced this type of "snow" problem before? If so, how
did you resolve it?
2) Is it possible that a driver update could resolve this type of problem?
Microsoft Troubleshooter suggests reinstalling the driver, but I wonder how
that could resolve a problem like this? I know, I know, this is Windows
we're talking about.
3) Microsoft Troubleshooter also suggested updating the BIOS! Sheesh! Like
I'm going to do that to a company-issued laptop!

Any ideas would be greatly appreciated!

- Dan