Well, I'm not sure why there has been no subsequent post?
Still, I've been continuing on exploring more options:
-- host-only networking and sharing the network from the mini card on the mac side.
-- bridged networking (thought that perhaps a vpn on the windows side might work - NO)
bridged networking does not seem to work for the mini card. so, scratch that. apparently parallels only bridges to airport/ethernet? perhaps not to a modem network (PPP)?
as for host-only, it seems to behave just as shared networking from the user perspective. the network works fine w/o vpn. bringing up a mac-side cisco vpn kills the network.
For host-only - the vpn cannot remain up if sharing is to both en2 and en3 (guest os nic and vm nic). but, sharing the mini card to only guest os nic (en2) allows the vpn to come up on the mac-side.
the problem seems to be that once the VPN is up, the windows nic cannot DHCP. it has the self-assigned address.
Much mucking around with re-iping from the windows side and restarting does not alter this behaviour. Once the VPN is up, windows is no longer on a network (though it believes that its cable is plugged into a network. So that leaves me to guess that something is not working for DHCP???!?)
thanks