Hi, I suppose you meant the german site http://www.debianforum.de/forum/viewtopic.php?t=55004.
The conclusion there is to not use the original Cisco VPN client but to use vpnc.
The post from tobi_w seems to be fine for you, I hope:
I'm using vpnc as Cisco client.
It is run completely in user space and doesn't require a kernel module, unlike Cisco client.
Install it by running "apt-get install vpnc"
You just have to edit /etc/vpnc.conf:
Interface name vpnlink
IPSec gateway xx.xx.xx.xx
IPSec ID GROUP_NAME
IPSec secret GROUP_PASSWD
Xauth username USERNAME
Xauth password PASSWD
Be sure you don't have space characters at the end of the lines.
Connect with "vpnc-connect" and disconnect with "vpnc-disconnect".