I was having the same kind of problem. I downloaded the latest drivers for the TNT/64 card which work on all my other games except Theme Park World and GP3/GP3-2000.
The keys wouldn't respond and my car would freeze at the begining of races (leaving me all alone on the starting grid) as well as during races. I read what drivers you used (30.82 version) and downloaded them. Thing is, I use Windows 98, and their for XP - DOH!
Anyway, I decided to install the original drivers (that came on the disc supplyed with the card) and it sorted out the problem. Note, when I bought the card, I downloaded the 45.23 instead of using the one's supplied on the disc.
I can now run the game at full frame complete with all detail in hardware mode.
Which makes me a happy racer.