Before when i couldn't get my agp to work (check my thread http://www.nvnews.net/vbulletin/show...threadid=22036
) i had to use NvAGP "1" and that would allow me to boot into X using just PCI and not agp. I noticed in your XF86Config you were using "2". Using "1" might let you get into the X server where it'll be a little easier to work on your agp issue.
Here is my output from /lib/libc.so.6.........
GNU C Library stable release version 2.3.2, by Roland McGrath et al.
Copyright (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
Compiled by GNU CC version 3.2.3.
Compiled on a Linux 2.4.20 system on 2003-05-18.
GNU libio by Per Bothner
crypt add-on version 2.1 by Michael Glad and others
linuxthreads-0.10 by Xavier Leroy
libthread_db work sponsored by Alpha Processor Inc
NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
Report bugs using the `glibcbug' script to <email@example.com>.
My system works fine in 32bit or 64 (in pci and agp now on 2.4.23) without the support you mentioned. I am also using beta 4620 drivers as well.