Serious ATI bug makes Vista virtually unusable for some

Over the past few weeks I've been working on trying to isolate a problem between Windows Vista and ATI graphics cards where the display driver stops responding and sometimes recovers and sometimes doesn't.

The error message that you get (if you're lucky and the system recovers) is this:

Display driver atikmdag stopped responding and has recovered

The bug also seems to occur when running Vista on a Mac using Boot Camp This problem is a real show stopper.  Even if your system recovers and continues working, you've had to put up with a lot of screen flicker and system slow downs while it crashes.  If the system doesn't recover then it's reboot time.  It can happen when you're gaming or within Windows, depending on how badly affected you happen to be. 

ATI/AMD know about this problem (which, from what I gather, dates back to when Vista was released) and here's what they have to say about it:

Symptoms:

When running games or full screen video, some users may be shown a message stating ATIKMDAG has stopped responding but was successfully recovered. In some cases, the system will continue to work as normal. Alternately, this error message may not result in the system being recovered and the system may need to be reset.

Solution: Currently there is no solution.

ATI Engineering has been advised of this issue and is investigating. Any updates will be published when they become available.

That's a lot of help.

As I said, I've been investigating this issue for some time now and have ruled out almost all of the voodoo surrounding this problem.  It's definitely not a hardware problem.  I've tested the system memory extensively using applications such as Memtest+ and tested system stability using programs such as Prime95.  I've also ruled out insufficient power from the PSU and defective graphics cards - the cards work fine under XP, but not under Vista.  Heat, another possible culprit, doesn't seem to be the reason either.  BIOS updates make no difference either.  Changing memory for modules from a different vendor also has no effect.

Some factors that seem to make the problem worse are:

• Multiple monitors
• 2GB+ of RAM
• All memory slots filled on motherboard

New drivers and installing all the Vista compatibility, reliability and stability updates (at least one update is meant to address this issue).  The bug also seems to occur when running Vista on a Mac using Boot Camp.

Bottom line, this is, without a doubt, a driver/Vista issue that requires urgent attention from ATI.  Yet another reason for gamers to give Vista a wide berth.

And, for what it's worth, a similar problem seems to affect Nvidia graphics cards.  The error is then Display driver nvlddmkm stopped responding and has recovered.