This is fixed in the lastest version in the repositories for Jaunty:
0.7.1~rc4.20090316+bzr21-0ubuntu2.
Using the Encryption combo box, select Weak (use with caution) to use
Single-DES encryption.
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gui does not support vnpc --enable-1des option
https://bugs.launchpad.net/bugs/295693
You
please check whether its fixed in the intrepid packages from network-
manager team PPA: http://launchpad.net/~network-manager/+archive
** Changed in: network-manager-vpnc (Ubuntu)
Status: New = Incomplete
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gui does not support vnpc --enable-1des option
