libx11-6 crash when ibus reset

[sjs_bebop]

I am getting a crash in x11 when using python3.3.2/tkinter8.6/ibus1.4.2 for Japanese input. All I need to do is open a python-tkinter entry window using ibus for input and reset ibus from its panel window. Below is a stack trace from a core file created with debug-compiled executable.

    GNU gdb (GDB) 7.5.91.20130417-cvs-ubuntu
    Copyright (C) 2013 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law. Type "show copying"
    and "show warranty" for details.
    This GDB was configured as "i686-linux-gnu".
    For bug reporting instructions, please see:
    <http://www.gnu.org/software/gdb/bugs/>...
    Reading symbols from /usr/bin/python3.3...done.

    warning: core file may not match specified executable file.
    [New LWP 20441]
    [New LWP 20442]

    warning: Can't read pathname for load map: Input/output error.
    [Thread debugging using libthread_db enabled]
    Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
    Core was generated by `/usr/bin/python3 ./WorldUnitsConvert.py'.
    Program terminated with signal 11, Segmentation fault.
    #0 0x00000153 in ?? ()
    (gdb) where
    #0 0x00000153 in ?? ()
    #1 0xb6cb9b91 in Xutf8LookupString () from /usr/lib/i386-linux-gnu/libX11.so.6
    #2 0xb70893bf in TkpGetString (winPtr=0xa4838f8, eventPtr=0xbfbcdac8,
        dsPtr=0xbfbcdb28)
        at /home/sjs/dev/python/tk8.6.0/unix/../unix/tkUnixKey.c:122
    #3 0xb70833ed in TransferXEventsToTcl (display=0xa239e10)
        at /home/sjs/dev/python/tk8.6.0/unix/../unix/tkUnixEvent.c:342
    #4 0xb708348a in DisplayCheckProc (clientData=0x0, flags=-3)
        at /home/sjs/dev/python/tk8.6.0/unix/../unix/tkUnixEvent.c:382
    #5 0xb6eb8676 in Tcl_DoOneEvent (flags=-3)
        at /home/sjs/dev/python/tcl8.6.0/generic/tclNotify.c:963
    #6 0xb715fe5c in Tkapp_MainLoop (selfptr=0xb71dd7a8, args=0xb70ed45c)
        at /home/sjs/dev/python/Python-3.3.2/Modules/_tkinter.c:2542
    #7 0x0821763c in PyCFunction_Call (func=0xb641276c, arg=0xb70ed45c, kw=0x0)
        at Objects/methodobject.c:81
    #8 0x08106adb in call_function (pp_stack=0xbfbcddc4, oparg=1)
        at Python/ceval.c:4063
    #9 0x08100dff in PyEval_EvalFrameEx (f=0xb71aa484, throwflag=0)
        at Python/ceval.c:2679
    #10 0x08104b51 in PyEval_EvalCodeEx (_co=0xb717abf0, globals=0xb72bdb5c,
        locals=0x0, args=0xb758da0c, argcount=1, kws=0xb758da10, kwcount=0,
        defs=0xb71b0358, defcount=1, kwdefs=0x0, closure=0x0)
        at Python/ceval.c:3433
    #11 0x08107041 in fast_function (func=0xb71b3bd4, pp_stack=0xbfbce614, n=1,
        na=1, nk=0) at Python/ceval.c:4161
    #12 0x08106c71 in call_function (pp_stack=0xbfbce614, oparg=0)
        at Python/ceval.c:4084
    #13 0x08100dff in PyEval_EvalFrameEx (f=0xb758d8cc, throwflag=0)
        at Python/ceval.c:2679
    #14 0x08104b51 in PyEval_EvalCodeEx (_co=0xb7207b88, globals=0xb72e67a4,
        locals=0xb72e67a4, args=0x0, argcount=0, kws=0x0, kwcount=0, defs=0x0,
        defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:3433
    #15 0x080f4c31 in PyEval_EvalCode (co=0xb7207b88, globals=0xb72e67a4,
        locals=0xb72e67a4) at Python/ceval.c:771
    #16 0x081365ca in run_mod (mod=0xa259258,
        filename=0xb72ab840 "./WorldUnitsConvert.py", globals=0xb72e67a4,
        locals=0xb72e67a4, flags=0xbfbceed8, arena=0xa21ddd0)
        at Python/pythonrun.c:1981
    #17 0x081363ee in PyRun_FileExFlags (fp=0xa252c60,
        filename=0xb72ab840 "./WorldUnitsConvert.py", start=257,
        globals=0xb72e67a4, locals=0xb72e67a4, closeit=1, flags=0xbfbceed8)
        at Python/pythonrun.c:1937
    #18 0x08134ad0 in PyRun_SimpleFileExFlags (fp=0xa252c60,
        filename=0xb72ab840 "./WorldUnitsConvert.py", closeit=1, flags=0xbfbceed8)
        at Python/pythonrun.c:1447
    #19 0x08133d5f in PyRun_AnyFileExFlags (fp=0xa252c60,
        filename=0xb72ab840 "./WorldUnitsConvert.py", closeit=1, flags=0xbfbceed8)
        at Python/pythonrun.c:1169
    #20 0x081569a7 in run_file (fp=0xa252c60,
        filename=0xb7567028 L"./WorldUnitsConvert.py", p_cf=0xbfbceed8)
        at Modules/main.c:306
    #21 0x081575ae in Py_Main (argc=2, argv=0xb7565028) at Modules/main.c:743
    #22 0x0805c8f6 in main (argc=2, argv=0xbfbcf074) at ./Modules/python.c:58
    (gdb) quit

[sjs_bebop (sjs-sonic)]

Here is a little more info. I installed libX11-6-dbg and the stack trace now also contains this:
    #0 0x00000153 in ?? ()
    #1 0xb6cb9b91 in Xutf8LookupString (ic=0xa3e79b0, ev=0xbfbcdac8,
        buffer=0xbfbcdb34 "", nbytes=199, keysym=0xbfbcdb0c, status=0xbfbcd99c)
        at ../../../src/xlibi18n/ICWrap.c:425
    #2 0xb70893bf in TkpGetString (winPtr=0xa4838f8, eventPtr=0xbfbcdac8,
        dsPtr=0xbfbcdb28)
        at /home/sjs/dev/python/tk8.6.0/unix/../unix/tkUnixKey.c:122