I fixed that problem. Turned out that the NVIDIA_kernel drivers weren't installing successfully because I didn't have the Linux kernel source code on my machine. Had to install it from the Linux CD's and bang, NVIDIA drivers install fine, it all works nicely. Oh, I ended up using the .tar.gz files.
But now I have another problem. I decided to use up2date and updated the kernel from 2.4.18-3 to 2.4.18-10 as well as the other things it told me to download.
Now of course the "Failed to initialize the NVdriver kernel module!" message is back. So I try to install the NVIDIA_kernel again and get the following message:
"make: *** No rule to make target '/lib/modules/2.4.18-3/build/include/linux/config.h', needed by 'nv.o'. Stop."
So the install doesn't work. Anyone any ideas on how to get round this?