lightdm crashed with SIGSEGV in emit_upstart_signal()

[howefield]

lightdm crashed with SIGSEGV in g_signal_emit_valist()

ProblemType: Crash
DistroRelease: Ubuntu 13.04
Package: lightdm 1.4.0-0ubuntu4
ProcVersionSignature: Ubuntu 3.8.0-6.13-generic 3.8.0-rc7
Uname: Linux 3.8.0-6-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.8-0ubuntu4
Architecture: amd64
Date: Sat Feb 16 13:57:00 2013
ExecutablePath: /usr/sbin/lightdm
InstallationDate: Installed on 2013-02-16 (0 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130216)
LightdmConfig:
 [SeatDefaults]
 user-session=ubuntu
 greeter-session=unity-greeter
MarkForUpload: True
ProcCmdline: lightdm
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
SegvAnalysis:
 Segfault happened at: 0x410518: mov 0x28(%rax),%ecx
 PC (0x00410518) ok
 source "0x28(%rax)" (0xaaaaaaaaaaaaaad2) not located in a known VMA region (needed readable region)!
 destination "%ecx" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: lightdm
StacktraceTop:
 ?? ()
 ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: lightdm crashed with SIGSEGV in g_signal_emit_valist()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

[Apport retracing service (apport)]

StacktraceTop:
 emit_upstart_signal (signal=0xb3d1e0 "@\322\263") at seat.c:303
 va_to_ffi_type (storage=<optimized out>, va=0xffffffffffffff88, gtype=0) at /build/buildd/glib2.0-2.35.8/./gobject/gclosure.c:1311
 g_cclosure_marshal_generic_va (closure=<error reading variable: Cannot access memory at address 0xffffffffffffff20>, closure@entry=<error reading variable: Cannot access memory at address 0x8>, return_value=<error reading variable: Cannot access memory at address 0xffffffffffffff30>, instance=<error reading variable: Cannot access memory at address 0xffffffffffffff68>, args_list=<optimized out>, marshal_data=<error reading variable: Cannot access memory at address 0xffffffffffffff18>, n_params=<error reading variable: Cannot access memory at address 0xffffffffffffff4c>, param_types=<error reading variable: Cannot access memory at address 0x10>) at /build/buildd/glib2.0-2.35.8/./gobject/gclosure.c:1525

[Launchpad Janitor (janitor)]

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