Well I just bought this today, and it seems like I have some sort of recurring problem. I start the game, and it runs fine for 5-10 minutes, then it starts doing a really odd glitch where everything useable (including the characters) turns yellow, and the area around the yellow objects turns blue. This leads to sound stuttering and game crashes. I'm also unable to use the menu when this happens as it just is a yellow screen, so I am unable to save and restart the game. If anyone else has this problem or knows how to fix it, let me know please. Thanks :)
I attached a couple of pictures of what it does when it glitches.

You might want to try running the game via 3DAnalyzer and see if that improves or removes the graphical glitches...

Where do I get that? I don't see anything about it in the forums here.. :(

http://www.3dfxzone.it/dir/tools/3d_analyze/index.php.
Don't be put off by the Italian bits ...there are some English words there too to guide you along ..

Ok I'll try it out. Also, if it helps. I'm using a AMD 920 Black Quad Core on a MSI K9A2 Platinum Mobo and have a GeForce 260 GTX OC on Win XP SP3. I dunno if it matters, but I'm guessing if the 3D Analyze doesn't fix it, that it's probably a problem with the video driver version or just the card itself as it most likely has all of the newer technology :)

This just happened to me as well. My game was playing fine and then it started to act a bit weird and then the people turned blue and the there was yellow squares around them.
The menu went wacky but I moved the mouse around in the menu (although you cannot tell it is a menu) and clicked I must have been over the Exit button because it dropped me to my desktop.
I am wondering if it is Nvidia cards. I just replaced mine today.
I had a 6800 running with no issues and I put a 9600 in today and started having problems.

Same thing happened here. Quite odd, actually. I'm under the impression that it happened right after a "zoom" event, so I'll disable the hardware zoom to see if it somehow solves the problem. I have a Geforce 8800GT.

The problem is still persisting even when using 3D Analyzer :( I hope we can get the GOG team to look into this since it doesn't seem to be an isolated problem.

Thought I'd chip in....
I'm getting a weird graphical bug if I use anything other than the software renderer (but that has sound problems when I use it).
If I select primary display driver or my Nvidia 8800gt, the graphics appear fine for the background, but all the player characters aren't drawn in fully (I see squares that partly make up the character).
At certain points the characters and monsters virtually dissapear and I'm left with the bracket graphic that identifies the selected player.
I've also had to add the ffdshow exlcusion in order to get the game to launch.
Tried newer nvidia drivers, even went as far as 185.68 beta's but still the same issues.
Not sure if any of the above helps, but I thought it was worth chipping in.
(Also tried the 3d test tool above, but no luck).
Thanks.

Wow! Thanks for the tip!
Soon as I get home, I'll check this out.

Sadly that hasn't worked for me.
I've added Gorky17.exe to the Nvidia Control Panel and turned off AA etc (tried lots of different combo's) but to no avail.
Thanks for the suggestion though.

Same problems here the characters simply disapear in hardware mode. i see boots but thats it. I have geforce 9800gtx tried the control panel 2 no joy

thought i would chip in aswell.
games doesnt work at all on my gma950 equipped netbook
i get black squares over the characters and enemies leaving just the bracket on my vista 32bit, 880gt based machine.

I also would like to chip in.

It says it's solved but so far i don't think solution helps, at the begining of the game characters begin to become invisible (more like there are invisible frames when a character walks in that part becomes invisible), I can only see bits and pieces of that character (a part of his arm, his boots etc...). The solution didn't help at all.