qjackctl hangs on startup

qjackctl hangs indefinitely during startup. It seems to be related to g_dbus (deadlock?):

Thread 2 (Thread 0x7f76ffa86700 (LWP 11151)):
#0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:132
#1 0x00007f770ebbe080 in _L_lock_903 () from /lib/x86_64-linux-gnu/libpthread.so.0
#2 0x00007f770ebbdf19 in __pthread_mutex_lock (mutex=0x18e2630)
    at pthread_mutex_lock.c:82
#3 0x00007f770c7305f4 in g_type_add_interface_static (instance_type=140148943623504,
    interface_type=140148943628384, info=0x7f76ffa85c00)
    at /build/buildd/glib2.0-2.34.1/./gobject/gtype.c:2819
#4 0x00007f7707ba1584 in g_socket_address_get_type ()
    at /build/buildd/glib2.0-2.34.1/./gio/gsocketaddress.c:72
#5 0x00007f7707bc1309 in g_unix_socket_address_get_type ()
    at /build/buildd/glib2.0-2.34.1/./gio/gunixsocketaddress.c:60
#6 0x00007f7707bc1488 in g_unix_socket_address_new_with_type (
    path=0x7f76f8001380 "/tmp/dbus-EedqcEAtax", path_len=<optimized out>,
    path_len@entry=-1, type=type@entry=G_UNIX_SOCKET_ADDRESS_ABSTRACT)
    at /build/buildd/glib2.0-2.34.1/./gio/gunixsocketaddress.c:426
#7 0x00007f7707bde236 in g_dbus_address_connect (error=0x7f76ffa85d28,
    cancellable=0x0, key_value_pairs=<optimized out>, transport_name=<optimized out>,
    address_entry=0x7f76f80010c0 "unix:abstract=/tmp/dbus-EedqcEAtax,guid=bc402a4ed15f0a66af21481c510ea7d4") at /build/buildd/glib2.0-2.34.1/./gio/gdbusaddress.c:577
#8 g_dbus_address_try_connect_one (
    address_entry=0x7f76f80010c0 "unix:abstract=/tmp/dbus-EedqcEAtax,guid=bc402a4ed15f0a66af21481c510ea7d4", out_guid=out_guid@entry=0x0, cancellable=cancellable@entry=0x0,
    error=error@entry=0x7f76ffa85d28)
    at /build/buildd/glib2.0-2.34.1/./gio/gdbusaddress.c:775
#9 0x00007f7707bdece5 in g_dbus_address_get_stream_sync (address=<optimized out>,
    out_guid=out_guid@entry=0x0, cancellable=cancellable@entry=0x0,
    error=error@entry=0x1a031e8)
    at /build/buildd/glib2.0-2.34.1/./gio/gdbusaddress.c:970
#10 0x00007f7707beefce in initable_init (initable=0x1a03180, cancellable=0x0,
    error=0x7f76ffa85dd8) at /build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:2566
#11 0x00007f7707b5fd51 in async_init_thread (res=0x1a17d60, object=<optimized out>,
    cancellable=<optimized out>)
    at /build/buildd/glib2.0-2.34.1/./gio/gasyncinitable.c:266
#12 0x00007f7707b9be3e in run_in_thread (job=<optimized out>, c=0x0, _data=0x1a26c70)
    at /build/buildd/glib2.0-2.34.1/./gio/gsimpleasyncresult.c:869
#13 0x00007f7707b8a236 in io_job_thread (data=0x19da880, user_data=<optimized out>)
    at /build/buildd/glib2.0-2.34.1/./gio/gioscheduler.c:162
#14 0x00007f770d093e62 in g_thread_pool_thread_proxy (data=<optimized out>)
    at /build/buildd/glib2.0-2.34.1/./glib/gthreadpool.c:309
#15 0x00007f770d093645 in g_thread_proxy (data=0x1a160a0)
    at /build/buildd/glib2.0-2.34.1/./glib/gthread.c:797
#16 0x00007f770ebbbe9a in start_thread (arg=0x7f76ffa86700) at pthread_create.c:308
#17 0x00007f770e3cecbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#18 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f770adc8780 (LWP 11150)):
#0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:132
#1 0x00007f770ebbe09b in _L_lock_1006 () from /lib/x86_64-linux-gnu/libpthread.so.0
#2 0x00007f770ebbe01c in __pthread_mutex_lock (mutex=0x19da930)
    at pthread_mutex_lock.c:101
#3 0x00007f770d0ace21 in g_mutex_lock (mutex=mutex@entry=0x1a031a0)
    at /build/buildd/glib2.0-2.34.1/./glib/gthread-posix.c:208
#4 0x00007f7707beec2d in initable_init (initable=0x1a03180, cancellable=0x0,
    error=0x0) at /build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:2527
#5 0x00007f7707bef5c1 in g_bus_get_sync (bus_type=bus_type@entry=G_BUS_TYPE_SESSION,
    cancellable=cancellable@entry=0x0, error=error@entry=0x0)
    at /build/buildd/glib2.0-2.34.1/./gio/gdbusconnection.c:6882
#6 0x00007f76fe9e6518 in g_daemon_vfs_init (vfs=0x1a60cc0) at gdaemonvfs.c:297
#7 0x00007f770c73098f in g_type_create_instance (type=<optimized out>)
    at /build/buildd/glib2.0-2.34.1/./gobject/gtype.c:1890
#8 0x00007f770c715288 in g_object_constructor (type=<optimized out>,
    n_construct_properties=0, construct_params=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1854
#9 0x00007f770c716d41 in g_object_newv (object_type=object_type@entry=27722912,
    n_parameters=n_parameters@entry=0, parameters=parameters@entry=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1637
#10 0x00007f770c71738c in g_object_new (object_type=object_type@entry=27722912,
    first_property_name=first_property_name@entry=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1547
#11 0x00007f7707b89f11 in try_implementation (extension=<optimized out>,
    verify_func=verify_func@entry=0x7f7707bb2a30 <g_vfs_is_active>)
    at /build/buildd/glib2.0-2.34.1/./gio/giomodule.c:645
#12 0x00007f7707b8a0a0 in _g_io_module_get_default (
    extension_point=extension_point@entry=0x7f7707c26b8c "gio-vfs",
    envvar=envvar@entry=0x7f7707c2f222 "GIO_USE_VFS",
    verify_func=verify_func@entry=0x7f7707bb2a30 <g_vfs_is_active>)
    at /build/buildd/glib2.0-2.34.1/./gio/giomodule.c:742
#13 0x00007f7707bb2e6e in g_vfs_get_default ()
    at /build/buildd/glib2.0-2.34.1/./gio/gvfs.c:199
#14 0x00007f7707b766ae in g_file_new_for_path (
    path=0x1a619b0 "/home/joh/.config/ibus/bus/1ef711f1d83d06d566a7bfa200000003-unix-0") at /build/buildd/glib2.0-2.34.1/./gio/gfile.c:6092
#15 0x00007f76fec2abaa in ?? () from /usr/lib/x86_64-linux-gnu/libibus-1.0.so.0
#16 0x00007f770c73098f in g_type_create_instance (type=<optimized out>)
    at /build/buildd/glib2.0-2.34.1/./gobject/gtype.c:1890
#17 0x00007f770c715288 in g_object_constructor (type=<optimized out>,
    n_construct_properties=0, construct_params=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1854
#18 0x00007f76fec28b45 in ?? () from /usr/lib/x86_64-linux-gnu/libibus-1.0.so.0
#19 0x00007f770c716d41 in g_object_newv (object_type=object_type@entry=27703664,
    n_parameters=n_parameters@entry=0, parameters=parameters@entry=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1637
#20 0x00007f770c71738c in g_object_new (object_type=27703664, first_property_name=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1547
#21 0x00007f76fec28b9a in ibus_bus_new ()
   from /usr/lib/x86_64-linux-gnu/libibus-1.0.so.0
#22 0x00007f76fee800da in ?? ()
   from /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/immodules/im-ibus.so
#23 0x00007f770c72e926 in type_class_init_Wm (pclass=0x1a5b820, node=0x1a6b510)
    at /build/buildd/glib2.0-2.34.1/./gobject/gtype.c:2217
#24 g_type_class_ref (type=type@entry=27702544)
    at /build/buildd/glib2.0-2.34.1/./gobject/gtype.c:2924
#25 0x00007f770c716df1 in g_object_newv (object_type=object_type@entry=27702544,
    n_parameters=n_parameters@entry=0, parameters=parameters@entry=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1623
#26 0x00007f770c71738c in g_object_new (object_type=27702544, first_property_name=0x0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gobject.c:1547
#27 0x00007f76fee80b92 in ibus_im_context_new ()
   from /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/immodules/im-ibus.so
#28 0x00007f77071d8026 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#29 0x00007f77071d8909 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#30 0x00007f77071d8bad in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#31 0x00007f770717dfda in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#32 0x00007f770c710140 in g_closure_invoke (closure=0x19a6a20, return_value=0x0,
    n_param_values=1, param_values=0x7fff220ced10, invocation_hint=0x7fff220cecb0)
    at /build/buildd/glib2.0-2.34.1/./gobject/gclosure.c:777
#33 0x00007f770c720e73 in signal_emit_unlocked_R (node=node@entry=0x19a6a50,
    detail=detail@entry=0, instance=instance@entry=0x1a34030,
    emission_return=emission_return@entry=0x0,
    instance_and_params=instance_and_params@entry=0x7fff220ced10)
    at /build/buildd/glib2.0-2.34.1/./gobject/gsignal.c:3481
#34 0x00007f770c7294af in g_signal_emit_valist (instance=0x1a34030,
    signal_id=<optimized out>, detail=0, var_args=var_args@entry=0x7fff220cef58)
    at /build/buildd/glib2.0-2.34.1/./gobject/gsignal.c:3300
#35 0x00007f770c729642 in g_signal_emit (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>)
    at /build/buildd/glib2.0-2.34.1/./gobject/gsignal.c:3356
#36 0x00007f77073105d0 in gtk_widget_realize ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#37 0x00007f770f7f8643 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#38 0x00007f770f7f8839 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#39 0x00007f770f7f8c55 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#40 0x00007f770f7ddcd9 in QGtkStyle::QGtkStyle() ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#41 0x00007f770f764c0b in QStyleFactory::create(QString const&) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#42 0x00007f770f4719f3 in QApplication::style() ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#43 0x00007f770f474375 in QApplicationPrivate::initialize() ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#44 0x00007f770f4744b2 in QApplicationPrivate::construct(_XDisplay*, unsigned long, unsigned long) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#45 0x00007f770f474d74 in QApplication::QApplication(int&, char**, int) ()
   from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#46 0x000000000041803f in ?? ()
#47 0x0000000000417317 in ?? ()
#48 0x00007f770e2fc76d in __libc_start_main (main=0x417286, argc=1,
    ubp_av=0x7fff220cfb48, init=<optimized out>, fini=<optimized out>,
    rtld_fini=<optimized out>, stack_end=0x7fff220cfb38) at libc-start.c:226
#49 0x0000000000417069 in ?? ()
#50 0x00007fff220cfb38 in ?? ()
#51 0x000000000000001c in ?? ()
#52 0x0000000000000001 in ?? ()
#53 0x00007fff220d1411 in ?? ()
#54 0x0000000000000000 in ?? ()
---
ApportVersion: 2.6.1-0ubuntu10
Architecture: amd64
DistroRelease: Ubuntu 12.10
InstallationDate: Installed on 2011-10-01 (492 days ago)
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110426)
MarkForUpload: True
NonfreeKernelModules: nvidia
Package: qjackctl 0.3.9-2
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 3.5.0-23.22-lowlatency 3.5.7.2
Tags: quantal
Uname: Linux 3.5.0-23-lowlatency x86_64
UpgradeStatus: Upgraded to quantal on 2013-01-06 (29 days ago)
UserGroups: adm admin audio cdrom dialout lpadmin plugdev sambashare vboxusers