compiz crashed when firefox restarting...(compiz assert failure: *** glibc detected *** compiz: free(): invalid pointer: 0xb6ff6ff4 ***)

[Ｖ字龍(Vdragon)]

It crashed after I restarted Firefox 7 when installing Xmarks and LastPass extension.
That's all I know: )

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity 4.18.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.19-generic-pae 3.0.4
Uname: Linux 3.0.0-12-generic-pae i686
ApportVersion: 1.23-0ubuntu2
Architecture: i386
AssertionMessage: *** glibc detected *** compiz: free(): invalid pointer: 0xb6ff6ff4 ***
Date: Fri Sep 30 20:19:04 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta i386 (20110901)
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=zh_TW:zh
 LANG=zh_TW.UTF-8
 SHELL=/bin/bash
Signal: 6
SourcePackage: unity
StacktraceTop:
 __libc_message (do_abort=2, fmt=0xb6fbc080 "*** glibc detected *** %s: %s: 0x%s ***\n") at ../sysdeps/unix/sysv/linux/libc_fatal.c:189
 malloc_printerr (action=<optimized out>, str=<optimized out>, ptr=0xb6ff6ff4) at malloc.c:6283
 _int_free (av=0xb6ff8400, p=0xb6ff6fec) at malloc.c:4795
 __GI___libc_free (mem=0xb6ff6ff4) at malloc.c:3738
 XFree () from /usr/lib/i386-linux-gnu/libX11.so.6
Title: compiz assert failure: *** glibc detected *** compiz: free(): invalid pointer: 0xb6ff6ff4 ***
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make Ubuntu better. This particular crash has already been reported and is a duplicate of bug #750386, 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.