Here is a suggestion from a Nvidia Geforce 3 user (yeah, I can help out on a TNT2!).  Anyways, Nvidia is known to make drivers that are nicer to the newer cards out there and not as nice with the older cards.  Thus, if you have an Nvidia card, and you are running the latest drivers, that is most likely your problem!  All in all, I downloaded a few different versions of Nvidia drivers and I only remember the results of my last drivers and my current ones.  I do remember running drivers version 30.82, but I think I changed from those because of major display errors with one game, Medal of Honor.  There is a lot of bad comments about the drivers version 40.72, but yet I was running those for a long time and decided I might as well change from those drivers to some new ones because a few games were having some display errors and besides I wanted to play around with some newer features.  So, I am now running drivers version 43.51 and they are working well for me, however they tend to make other Geforce 3s not run that well.

The rundown is that if you have an older card then the newer the drivers you get, the worse your card performs and acts in games.  Generally, you have to get drivers that are around your card's age.  Any Nvidia driver can run any older Nvidia card (with a few rare exceptions) but running the card and running it well are two different things.  All I can say is that you should ask around various video card forums and try out a few drivers for yourself until the visual problems go away.  Everybody's video card is different (the boards being made by different companies... I think mine was made by Pinegroup) and everybody's setup is different.  So start into the drivers at a few recomended driver version numbers and go on from there.  I recommend you go to the site below for the specific drivers and some help in the forums (the forums seem a bit chaotic to me).  Note, for some reason, that site is down today... so keep trying and I will keep you posted as to if the site reappears.  I do know that there is some place in the forums which say what range of drivers (as in, version numbers) you should be running with your card and I'll link to that whenever they come back online.

http://guru3d.com/

Guru3d is back online.  Here is some research.

the following is in relation to the TNT2 card
<< See 3rd post down >>

The following person had MAJOR trouble with the 44.03 drivers although they are using a Geforce 4, however it may have been configuration issues and not driver trouble.
<< Read whole thread >>

Another Geforce 4 card, this one driver trouble with the 44.04 drivers, which is Creative's 44.03 drivers (thus, unofficial)...
<< Read whole thread >>

In relation to the 44.03, apparently there is some issues with DirectDraw and these drivers...
<< This quote is from somewhere on the second page >>

Just a random thing I am reading in a lot of threads, a LOT of people love 30.82 drivers, although some people don't.  the 40 series and higher were optimised for the FX cards, I believe.

This thread talks about a person having resolution problems with 44.03 drivers, another Geforce 4 user...
<< read thread >>

Since I am kinda sick and tired of looking through the Guru3D forums, for now... I'll end on this note.  People comparing driver version numbers, and a bit of good advice at the end...
<< read thread >>

Good luck and keep trying new drivers until things work better for you or you give up hope... that seems to be the way things are with Nvidia video cards!  

PS -- My Geforce 3 is running on 43.51 drivers.  It works well for my system, but I don't know how it reacts with other cards.  You milage may very.

my cristallid nebulas have green sqares too ... perhaps there is a mistake in the sod ? (have geforce mx/mx400)