There is a site (http://www.linuxquestions.org/questions/linux-software-2/cisco-vpn-client-353630/) that may have the answer that you need.
Here are the steps that may apply to your issue....
5. Do a uname -r to find the correct kernel-headers for your build.
6. Use synaptic to search and install the correct kernel-HEADERS, not source.
7. Untar your Cisco Client, go to the vpnclient folder and do a sudo sh vpn_install
8. Answer all questions, the defaults worked for me.
9. make sure you start the vpn sub-system with
sudo /etc/init.d/vpnclient_init start
10. Copy your .pcf profile to the sudo cp /etc/opt/cisco-vpnclient/Profiles.
11. Do a vpnclient connect (without the .pcf extention)
Hope this helps.