I was having some of the same problems that others were having with glitches while using the texturen mod. The glitches were of floating objects, paint brushed looking objects, ect... The weird part was that the mod worked when I first installed it. After uninstalling it and reinstalling it the mod started to glitch.
The majority of answers to this problem was that the video card was insufficient to run the mod. The difference between my problem and the others that I have seen is that my video card is more than adequate to run this mod plus (I have a NVIDIA GeForce GTX 560 Ti). After a few hours of troubleshooting I finally figured out the very simple solution to this problem.
The problem was that when I reinstalled The Witcher all of the settings were reset. It seems that when the graphic settings are low the mod glitches. All that I had to do to fix the problem was to turn all of the graphic settings up, I put them to max and the mod worked perfectly.
Hope this helps anyone else that is having the same problem.

This may be resurrecting an old post but this helped so much, couldn't figure out why my new 680 gtx was having problems running this. I couldn't run it on my 8800 that I upgraded from. Didn't even see the settings, thought they would be under video not advanced, stupid mistake. Thank you.