[Dell Optiplex XE] input/output not rerouted to external jack

When headphones or a microphone is connected to the external jacks on a Dell Optiplex XE, sound input or output is not rerouted to the external connectors. E.g. sound output still goes through the internal speaker when headphones are connected. External mic is not recognized at all.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: alsa-base 1.0.22.1+dfsg-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.32-21.32-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-21-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: ubuntu 1165 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfe6fc000 irq 16'
   Mixer name : 'Realtek ALC269'
   Components : 'HDA:10ec0269,102802fb,00100100'
   Controls : 10
   Simple ctrls : 6
Date: Tue May 25 01:24:04 2010
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
PackageArchitecture: all
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.UTF-8
SelectedCard: 0 Intel HDA-Intel - HDA Intel
SourcePackage: alsa-driver
Symptom: audio
Title: [HDA-Intel - HDA Intel] ALSA test tone not correctly played back
dmi.bios.date: 12/01/2009
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A00
dmi.board.name: 01KD4V
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 15
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA00:bd12/01/2009:svnDellInc.:pnOptiPlexXE:pvr:rvnDellInc.:rn01KD4V:rvrA00:cvnDellInc.:ct15:cvr:
dmi.product.name: OptiPlex XE
dmi.sys.vendor: Dell Inc.