Dell Latitude E6510 - No headphone output after a reboot from Windows 7

Steps to reproduce :
1) Boot on Windows 7
2) Reboot on Ubuntu

What happens : sound output on the speakers but not on the headphones. Reboots does nos solve the problem.
Solution : shutdown the computer. Start it again on Ubuntu.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: alsa-base 1.0.23+dfsg-1ubuntu4
ProcVersionSignature: Ubuntu 2.6.35-28.49-generic-pae 2.6.35.11
Uname: Linux 2.6.35-28-generic-pae i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: julien 1792 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf6960000 irq 48'
   Mixer name : 'Intel IbexPeak HDMI'
   Components : 'HDA:111d76d5,1028040b,00100104 HDA:80862804,80860101,00100000'
   Controls : 22
   Simple ctrls : 11
Date: Sat Mar 26 20:10:36 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, user)
 LANG=fr_FR.utf8
 SHELL=/bin/bash
SelectedCard: 0 Intel HDA-Intel - HDA Intel
SourcePackage: alsa-driver
Symptom: audio
Title: [IDT 92HD81B1C5] ALSA test tone not correctly played back
dmi.bios.date: 08/10/2010
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A05
dmi.board.name: 02K3Y4
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA05:bd08/10/2010:svnDellInc.:pnLatitudeE6510:pvr0001:rvnDellInc.:rn02K3Y4:rvrA01:cvnDellInc.:ct9:cvr:
dmi.product.name: Latitude E6510
dmi.product.version: 0001
dmi.sys.vendor: Dell Inc.