compiz crashed with SIGSEGV in CompWindow::id()

[Carla Sella]

do not know I had just reported a bug on remmina and saw also this crash, but do not know what caused it.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: unity 5.2.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-12.21-generic 3.2.2
Uname: Linux 3.2.0-12-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.91-0ubuntu1
Architecture: amd64
CrashCounter: 1
Date: Sat Feb 4 21:56:23 2012
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120114)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0x43f4c4 <_ZN10CompWindow2idEv+4>: mov 0x20(%rax),%rax
 PC (0x0043f4c4) ok
 source "0x20(%rax)" (0x00000091) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 CompWindow::id() ()
 unity::UnityWindow::glPaint(GLWindowPaintAttrib const&, GLMatrix const&, CompRegion const&, unsigned int) () from /usr/lib/compiz/libunityshell.so
 GLWindow::glPaint(GLWindowPaintAttrib const&, GLMatrix const&, CompRegion const&, unsigned int) () from /usr/lib/compiz/libopengl.so
 PrivateGLScreen::paintOutputRegion(GLMatrix const&, CompRegion const&, CompOutput*, unsigned int) () from /usr/lib/compiz/libopengl.so
 GLScreen::glPaintOutput(GLScreenPaintAttrib const&, GLMatrix const&, CompRegion const&, CompOutput*, unsigned int) () from /usr/lib/compiz/libopengl.so
Title: compiz crashed with SIGSEGV in CompWindow::id()
UpgradeStatus: Upgraded to precise on 2012-01-31 (4 days ago)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo vboxusers

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #916770, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.