ati2mtag -- Edid Checksum Error (DAL -- 43033)

One of my ATI-nVidia-AMD-WindowsXP workstations has recently developed some seriously stability issues.

I am using an ATI Radeon X1800 on with the AMD Athelon 64 X2 Dual Core 4400+. Not a brand new system, but not too old either.

The machine, under load, will spontaneously reboot and the only evidence of a system problem is an Event Log entry from "ati2mtag" stating Edid checksum error. This reboot (for me at least) would do one of these things:

• put both monitors into PowerSave mode, freeze all input & disable NumLock -- but not reboot. In this case the soundcard would issue a loop of recent input make terrible screeching sounds
  
• Freeze the output to the monitor (leaving the screen frozen, in either a screensaver or the UI of whatever was running), freeze mouse input & disable Keyboard/Numlock -- but not reboot. Sometimes, in this case the soundcard would issue a loop of recent input make terrible screeching sounds
• Issue an immediate hard reset to the machine and reboot immediately without warning
  

I have upgraded my drivers, disabled Edid checking in Catalyst and it is still happening.

I am not certain but I believe it may be temperature related.

http://forums.techarena.in/showthread.php?t=882129
http://www.techsupportforum.com/hardware-support/video-card-support/207822-pc-restarting-occures-only-wc3-2.html
http://www.driverheaven.net/hardware-discussion-support/144512-x1650-issues.html

I performed about every settings change and drive update I could think of to resolve this issue. Once I disabled all EDID Checksum Error generating functionality, I was still having the sudden unplanned system reboots, but I had eliminated the Event Log entry.

So, following the temperature hunch I took the case part, cleaned everything, removed a few panels that were blocking air flow. Following these changes I monitored the VPU's core temperature via Catalyst's OverDrive control-panel, which allows you to view the temperature even if you are not enabling overclocking (which I am not.)

Removing all the dust and making some minor tweaks to the case reduced the temperature from 71C to 62C on average.