Here's how it goes:
I install the game, the update patch, several patches (including court patches for every court by just dumping the files to sgsm -folder).
I start the game, everything runs smoothly... I start to play a game ---> somewhere during the game the screen freezes for like 5 seconds and when the game goes on again, it looks like: THIS (the pic isn't the best possible, but it should show you what the problem is...)
The back wall of every court looks like small squares and if I shoot the ball, then I can't see it before it's beneath the basket (guys understand?)
After it occurs the first time, it bothers all the time until I uninstall the game, delete the all the folders and then install the game again...
The menu screen also "crashes" like the courts so, that all the animations (pop-up player name, videos etc.) have also the small squares on them... (that's why I think it's not the court patches that bother...)
I really appreciate, if someone could help me

thanks in advance for all the help

add: My graphics card is an old nVidia GeForce FX 5600 (AGP port) something like 3,5 years old.
BUT, I did play totally normal games before this bug appeared... It just came like a lightning from a clear sky...