lighdm and pulseudio startup error...

[marcobra (Marco Braida)]

Description: Ubuntu 13.04
Release: 13.04

lightdm:
  Installato: 1.6.0-0ubuntu2.1
  Candidato: 1.6.0-0ubuntu2.1
  Tabella versione:
 *** 1.6.0-0ubuntu2.1 0
        500 http://archive.ubuntu.com/ubuntu/ raring-updates/main i386 Packages
        100 /var/lib/dpkg/status
     1.6.0-0ubuntu2 0
        500 http://archive.ubuntu.com/ubuntu/ raring/main i386 Packages

pulseaudio:
  Installato: 1:3.0-0ubuntu6
  Candidato: 1:3.0-0ubuntu6
  Tabella versione:
 *** 1:3.0-0ubuntu6 0
        500 http://archive.ubuntu.com/ubuntu/ raring/main i386 Packages
        100 /var/lib/dpkg/status

The system at send a message telling "file not found" give an enter made the system continue

Seems this error i see it into system log...

...
May 1 22:10:11 localhost pulseaudio[2193]: [pulseaudio] authkey.c: Failed to open cookie file '/var/lib/lightdm/.config/pulse/cookie': File o directory non esistente
May 1 22:10:11 localhost pulseaudio[2193]: [pulseaudio] authkey.c: Failed to load authorization key '/var/lib/lightdm/.config/pulse/cookie': File o directory non esistente

Thank you

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: lightdm 1.6.0-0ubuntu2.1
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic i686
ApportVersion: 2.9.2-0ubuntu8
Architecture: i386
Date: Wed May 1 21:39:11 2013
InstallationDate: Installed on 2011-07-11 (659 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
LightdmConfig:
 [SeatDefaults]
 greeter-session=unity-greeter
 user-session=ubuntu
MarkForUpload: True
SourcePackage: lightdm
UpgradeStatus: Upgraded to raring on 2013-04-27 (3 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Michael Blank (mblank)]

this same bug also happens in Ubuntu 14.10

[Prashant (pdborhad)]

Every time whenever this bug occur, the machine reboots. Any workaround for this bug?