I upgraded a machine to Ubuntu Feisty Fawn (7.10) today and was having trouble recompiling the Cisco VPN client. Thanks to
this thread, I went to
this blog post and applied
this patch and everything was fine.
I must admit that applying some random patch to one's VPN client inspires a moderate amount of queasiness, but fortunately the patch is simple enough to understand so one can be confident no mischief is involved.