[quietjim]

I bought a MacBook Pro about a month ago; matte display. It gets hooked back and forth to a Cinema Display at the office.

Recently, I've noticed that every once in a while...perhaps once a week... the screen suddenly becomes full of a kaleidoscope of colors and the machine freezes, responding only to a full restart with the power button. It reminds me a bit of a particular sort of old Apple //e crash actually.

I wondered if anyone else had seen this behavior. I assume it has something to do with the graphics chip. This is the info about that...
GeForce 8600M GT:

Chipset Model: GeForce 8600M GT
Type: Display
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 512 MB
Vendor: NVIDIA (0x10de)
Device ID: 0x0407
Revision ID: 0x00a1
ROM Revision: 3212
Displays:
Color LCD:
Display Type: LCD
Resolution: 1440 x 900
Depth: 32-bit Color
Built-In: Yes
Core Image: Hardware Accelerated
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Supported
Display Connector:
Status: No display connected

[Cold Warrior]

Does the hardware test reveal anything?

[shrugs*]

Visual artifacts are sometimes signs of halting from overheating.

Is there a pattern at all to when it happens?

e.g.
Only when ..
- Using the external display
- Running a certain program
- Using apps that are graphics-intense
- The notebook is in clamshell mode
- The notebook at on my desk at home/office

It'd be a good start to look at the system logs using 'Console' (in Application/Utilities) and see if there's any related messages. Also, maybe keep an eye on system temperatures. I'm sure there are some apps available to log it, but at a glance there's a widget called iStat Pro that displays most temp info.