# cd /usr/src/kernels/2.6.16-1.2069_FC4-i686
# uname -r > .kernelrelease
# make kernelrelease
2.6.16-1.2069_FC4

I only speak english, so if someone could translate:
The above fixes the problem with the Cisco VPN Client build with 2.6.16-1.2069_FC4.