Well, it looks like I've got it working now. For anyone else who runs into this, here is what I ended up doing.
I had to download a newer version of vpnclient which I found here.
[www.tuxx-home.at] - Website of Alexander Griesser | New Cisco VPN Client 4.8.01.0640-k9 compiles on 2.6.22 out of the box!
I had vpnclient-linux-x86_64-4.8.00.0490-k9.tar.gz and the new version was vpnclient-linux-x86_64-4.8.01.0640-k9.tar.gz.
After downloading the new version I had to apply the 2.4 patch from
http://projects.tuxx-home.at/ciscovp....24-final.diff
Ares:/opt/vpnclient # patch < ./vpnclient-linux-2.6.24-final.diff
patching file GenDefs.h
patching file interceptor.c
Ares:/opt/vpnclient #
This was by far the cleanest output I've gotten. After this the install went perfectly.