Mark Bergsma and I successfully debugged this issue, which may previously have been hidden by a g++ misfeature/bug. Mark's fix is in http://wiki.powerdns.com/projects/trac/changeset/876 - which also addresses some other geobackend issues.
Thanks for the bug report, and thanks to Mark for the quick response! -- http://www.PowerDNS.com Open source, database driven DNS Software http://netherlabs.nl Open and Closed source services -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]