I switched runlevels to level 3 with init, and at other times by editing /etc/inittab.
The enterprise kernel uses the same source as the standard kernel, just with a different configuration; thus (ls /usr/src)
linux -> linux-2.4.22-26mdk/
The driver nvidia.o seemed to appear in the right place after the compilation (/lib/modules/2.4.22-26mdkenterprise/kernel/drivers/video) and it was possible to load it manually (modprobe).
Does your driver also appear there?
By the way, what do you get with this test:
/lib/libc.so.6 | grep "Thread-local storage support included."
(I get no output). I am wondering why I am running into the problem with TLS with the 4496 driver...