lpadmin -d does not set default printer

Binary package hint: cups

Use case: systems with multiple printers where you want to change the default printer
For example:
~$ lpstat -d -a
system default destination: hp1300n-system
hp1300n-system accepting requests since Thu Sep 16 15:32:35 2010
iR5000i-Z accepting requests since Thu Aug 26 11:33:03 2010
pdf-wkb accepting requests since Wed Aug 4 11:13:17 2010
Q2-Z accepting requests since Thu Sep 9 14:41:19 2010

For example, change the default printer to Q2-Z
~$ lpadmin -d Q2-Z
~$ lpstat -d -a
system default destination: hp1300n-system
hp1300n-system accepting requests since Thu Sep 16 15:32:35 2010
iR5000i-Z accepting requests since Thu Aug 26 11:33:03 2010
pdf-wkb accepting requests since Wed Aug 4 11:13:17 2010
Q2-Z accepting requests since Thu Sep 9 14:41:19 2010

hp1300n-system is still the default printer. The user didn't get confirmation of the change, nor a message explaining why the requested printer was not set as the default.

What should have happened:
Q2-Z should be set as the default printer

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: cups-client 1.4.3-1ubuntu1.2
ProcVersionSignature: Ubuntu 2.6.32-24.43-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-24-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
CupsErrorLog: E [21/Sep/2010:09:09:56 +0200] Unable to remove temporary file "/var/spool/cups/tmp/.hplip" - Is a directory
Date: Tue Sep 21 14:07:56 2010
Lpstat:
 device for hp1300n-system: socket://hp1300n-system:9100
 device for iR5000i-Z: lpd://zfs-front/iR5000i-Z
 device for pdf-wkb: lpd://zfs-front/pdf-wkb
 device for Q2-Z: lpd://zfs-front/Q2-Z
Papersize: a4
PpdFiles:
 iR5000i-Z: Canon iR5000i-6000i PS
 Q2-Z: Canon iPR Server Q2 V2.0 (US)
 hp1300n-system: HP LaserJet 1300n hpijs pcl3, 3.10.2
 pdf-wkb: Acrobat Distiller 3011.104
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.32-24-generic root=/dev/mapper/vg0-root ro splash
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=C
 SHELL=/bin/bash
SourcePackage: cups
dmi.bios.date: 06/15/2010
dmi.bios.vendor: Intel Corp.
dmi.bios.version: TMIBX10H.86A.0038.2010.0615.1502
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: DQ57TM
dmi.board.vendor: Intel Corporation
dmi.board.version: AAE70931-401
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrTMIBX10H.86A.0038.2010.0615.1502:bd06/15/2010:svntranstecAG:pn:pvr:rvnIntelCorporation:rnDQ57TM:rvrAAE70931-401:cvn:ct3:cvr:
dmi.sys.vendor: transtec AG