Ok, I tried again, and this time it wouldn't compile at all.
I tried re-installing the kernel source, but it still can't compile the nvidia.ko module.
Eventually, I messed around with the wrong setting and cabbaged my system.
So, I have a clean system now, with only the kernel source 2.6 and kernel source stripped 2.6 installed, and it still can't compile.
I would post the nvidia installer log file, but I don't know much about file permissions under Linux, and every time I try to copy it, it's still a root owned file.
Kind of embarrassing, but I've never had to swap file ownership before
Any help would be appreciated