Has 10.6.7 broken the built-in Cisco IPSec VPN client?
Not sure if it's the same issue, but I've had problems with the 10.7 built-in Cisco IPSec client from within my work network - there are some cryptic references (i.e. tech-speak I don't understand) to what Apple changed at the bottom of this support discussion.

Switching over to a tethered 3G connection fixed the problem. I mention it here in case someone stumbles across this page &amp; it helps them.