Sorry, I forgot to mention that in my case at least, the ad-hoc network in question had no encryption and was created by an XP SP2 machine using the network creation wizard and the Internet connection sharing service.
-- ad-hoc networks don't work with ipw2200 https://launchpad.net/bugs/75358 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs