So they upgraded my laptop at work to Snow Leopard, but left the Cisco VPN v4.9 client on the system. This was creating all sorts of problems, since the Cisco VPN client doesn’t support Snow Leopard (you use the built-in VPN instead), and it doesn’t play well with Parallels. Problems like, on occasion, the laptop would not wake up when it is put to sleep with a VPN connection via the airport wireless connection in our infrastructure, and on occasion the laptop would simply not boot at all.

So here’s how to uninstall the Cisco VPN client, nicked from I Found This Useful:

Running Terminal, type in the following command:

sudo /usr/local/bin/vpn_uninstall

Give it your administrator password, and answer yes to the questions. (The Snow Leopard VPN settings are apparently stored elsewhere.)

Now my laptop at work runs better.