I hear "the Ubuntu drums" after boot-up prior to sign on, then no sound at all beyond that. [Latitude D620, SigmaTel STAC9200, Speaker, Internal] No sound at all

[Stoney Manning]

Problem only occurred after 12.04 installed. Sound worked fine with 11.10

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: pulseaudio 1:1.1-0ubuntu15
ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14
Uname: Linux 3.2.0-24-generic i686
NonfreeKernelModules: nvidia
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu7
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: stoney 1648 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xefffc000 irq 44'
   Mixer name : 'SigmaTel STAC9200'
   Components : 'HDA:83847690,102801c2,00102201 HDA:14f12bfa,14f100c3,00090000'
   Controls : 14
   Simple ctrls : 7
Date: Thu May 10 21:41:28 2012
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: pulseaudio
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:Intel successful
Symptom_Card: Built-in Audio - HDA Intel
Symptom_DevicesInUse:
 1648/dev/snd/controlC0: stoney F.... pulseaudio
 AND
Symptom_Jack: Speaker, Internal
Symptom_PulsePlaybackTest: PulseAudio playback test failed
Symptom_Type: No sound at all
Title: [Latitude D620, SigmaTel STAC9200, Speaker, Internal] No sound at all
UpgradeStatus: Upgraded to precise on 2012-04-28 (12 days ago)
dmi.bios.date: 05/16/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.name: 0KX350
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd05/16/2008:svnDellInc.:pnLatitudeD620:pvr:rvnDellInc.:rn0KX350:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude D620
dmi.sys.vendor: Dell Inc.