rather than messing with CC=gcc32 or IGNORE_CC_MISMATCH, here's an alternative way of installing your nvidia drivers (at least, it works for me, so i'm open to corrections/clarifications).

download the latest nvidia driver from www.nvidia.com,
NVIDIA-Linux-x86-1.0-4496-pkg2.run. don't try to install it, just extract it into a directory with:

$ sh NV...run --extract-only

now, as root, "cd" into that directory and just run "make install". that should build the driver and install it. because you're actually compiling the driver, you're pretty likely to not have to worry about any compiler mismatches.

but wait -- there's more.

if you're running the 2.6.0-xxx kernel, go to www.minion.de, and grab the single diff file NVIDIA_kernel-1.0-4496-2.6.diff. (note: while i'm grateful for that site, i find the explanation there virtually
incomprehensible.)

apply that single diff file against the nvidia directory you extracted, in the subdirectory .../usr/src/nv, then create the single symlink Makefile -> Makefile.kbuild. return to the top level nvidia directory and, once again,

# make install

every time you boot under a new kernel, the previous nvidia module won't be any good, so just head back to your nvidia directory and rerun "make isntall".