Xcode 4 + iOS 4.3: “No Packager exists for the type of archive”

I just upgraded to Xcode 4 and am trying to create an adhoc build of an earlier project. Whenever I use the "Archive" option I either end up with no archive at all in the Organizer window OR there is an archive, but there is no option to package it as an .ipa, because "No Packager exists for the type of archive".

Has anyone gotten adhoc builds working under Xcode 4 for project that have been migrated from Xcode 3.2?