Bug 792309 is fixed now. Please try the new CUPS packages (1.4.6-7 on Debian unstable and Ubuntu Oneiric, 1.4.6-5ubuntu1.4 as SRU for Ubuntu Natty, see bug 792309) as soon as they get available and tell here whether the change fixes your problems and whether then even AirPrint works without any additional Avahi service definition file.
Bug 792309 is fixed now. Please try the new CUPS packages (1.4.6-7 on Debian unstable and Ubuntu Oneiric, 1.4.6-5ubuntu1.4 as SRU for Ubuntu Natty, see bug 792309) as soon as they get available and tell here whether the change fixes your problems and whether then even AirPrint works without any additional Avahi service definition file.