Hello guys n' gals of gog.com!
I was wondering if anyone else has encountered a certain graphical bug and have possibly found a fix for it.
After playing Gothic between 5 to 10 minutes, the entire floor disappears and becomes translucent, never to return. The game then crashes after awhile (I wait to see if the floor returns), and I can't even load a saved game because the flooring is still gone, even if the save was in a different area!
I have the playerkit, fps, texture, and ironkeep patches installed. I don't think its any of the patches because I have played without any of them before all this started to happen. I have also uninstalled and reinstalled Gothic about 3 or 4 times seeing if maybe something went wrong with the installation. Another thing is that I would try old saved games as well as new games to no avail.
I have Windows Vista Ultimate 32 bit; an nvidia 8800gt with the newest drivers; Q6600 cpu intel quad core; and 4 gigs of ram.
I've looked around on these forums and for the most part haven't found anyone else that has had this exact same problem.
Any comments or suggestions are appreciated! :D

I have neither Windows Vista nor Nvidia card, so everything I say is just a wild speculation. Gothic 1 and 2 apparently have problems with newer Nvidia drivers as it can be seen in this thread on GOG:
http://www.gog.com/en/forum/gothic_series/game_crashes_when_going_outside
or here:
http://forums.nvidia.com/index.php?showtopic=104636&st=0
The only thing I can suggest is to wait for Nvidia to sort it out with their drivers or try earlier driver version (it helped some people, but I can't remember the driver version, I will see if I can find it later).
Maybe others will have more helpful suggestions.

I can not speak for the GOG Versions of these games but I am running Vista 64 with an AMD Phenom Processor and ATI 4890 video and have no issues with loading or playing these games (Retail and Patched) at all. I am guessing it is the NVIDIA and drivers. They seem to have a lot of issues with the older games.

I have had a bit of a breakthrough. After I start the game up and when the floor dissapears, I was messing around with the video settings and found a temporary solution.
I haven't played it longer than around 5 minutes (due to school studies, I haven't been able to play much), but it does seem to fix itself if I change the resolution to one of the 16 bit versions.
The 32 bit resolutions all seem to wanna make the floor dissapear. Hopefully this might help someone or if someone is having the same problem can try changing the resolution.
Thanks guys!