After upgrading to Thunderbird 11 I experience frequent hangs of Thunderbird.  I'm using IMAP.  Here is an strace and stacktrace:

$ strace -p 3046
Process 3046 attached - interrupt to quit
futex(0x7f00ba56d0e8, FUTEX_WAIT_PRIVATE, 2, NULL

$ gdb -p 3046

#0  0x00007f00bb3f0be4 in __lll_lock_wait ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007f00bb3ec21b in _L_lock_1031 ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#2  0x00007f00bb3ec19c in pthread_mutex_lock ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#3  0x00007f00b60e45a9 in PR_Lock (lock=0x7f00ba56d0e8)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/nsprpub/pr/src/pthreads/ptsynch.c:206
#4  0x00007f00b60e4bc5 in PR_EnterMonitor (mon=0x7f00ba56d0e0)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/nsprpub/pr/src/pthreads/ptsynch.c:561
#5  0x00007f00b60d53c1 in PR_CEnterMonitor (address=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/nsprpub/pr/src/threads/prcmon.c:380
#6  0x00007f00b9218f96 in nsImapProtocol::PseudoInterruptMsgLoad (
    this=0x7f008b806800, aImapFolder=0x7f009a3a6038, aMsgWindow=0x0, 
    interrupted=0x7fff61c43e30)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/imap/src/nsImapProtocol.cpp:1280
#7  0x00007f00b91f2dd9 in nsImapIncomingServer::PseudoInterruptMsgLoad (
    this=0x7f00aac560c0, aImapFolder=0x7f009a3a6038, aMsgWindow=0x0, 
    interrupted=0x7fff61c43e30)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/imap/src/nsImapIncomingServer.cpp:2245
#8  0x00007f00b9210fb8 in nsImapMailFolder::DeleteMessages (
    this=0x7f009a3a6000, messages=0x7f009c2ae860, msgWindow=0x0, 
    deleteStorage=true, isMove=false, listener=0x0, allowUndo=false)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/imap/src/nsImapMailFolder.cpp:2279
#9  0x00007f00b91c8406 in nsMsgComposeSendListener::RemoveCurrentDraftMessage (
    this=0x7f00888e6240, compObj=0x7f0089213250, calledByCopy=false)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgCompose.cpp:3798
#10 0x00007f00b91d1487 in nsMsgComposeSendListener::OnStopSending (
    this=0x7f00888e6240, 
    aMsgID=0x7f008bb8c550 "<email address hidden>", aStatus=0, 
    aMsg=0x0, returnFile=0x0)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgCompose.cpp:3623
#11 0x00007f00b91a3cb0 in nsMsgComposeAndSend::NotifyListenerOnStopSending (
    this=<optimized out>, aMsgID=<optimized out>, aStatus=<optimized out>, 
    aMsg=<optimized out>, returnFile=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgSend.cpp:3991
#12 0x00007f00b91ab492 in nsMsgComposeAndSend::DoDeliveryExitProcessing (
    this=0x7f009a806e20, aUri=<optimized out>, aExitCode=0, 
    aCheckForMail=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgSend.cpp:3856
#13 0x00007f00b91ab4c1 in nsMsgComposeAndSend::DeliverAsMailExit (
    this=<optimized out>, aUrl=<optimized out>, aExitCode=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgSend.cpp:3876
#14 0x00007f00b91a45db in SendDeliveryCallback (aExitCode=0, 
    aUrl=<optimized out>, this=<optimized out>, 
    inIsNewsDelivery=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgSend.cpp:3437
#15 nsMsgComposeAndSend::SendDeliveryCallback (this=<optimized out>, 
    aUrl=<optimized out>, inIsNewsDelivery=<optimized out>, 
    aExitCode=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgSend.cpp:3397
#16 0x00007f00b91a4238 in MsgDeliveryListener::OnStopRunningUrl (
    this=0x7f0096aa3c40, url=0x7f00896f7be8, aExitCode=0)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsMsgSend.cpp:277
#17 0x00007f00b9100cba in SetUrlState (aExitCode=0, 
    aRunningUrl=<optimized out>, this=0x7f00896f7be8)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/base/util/nsMsgMailNewsUrl.cpp:135
#18 nsMsgMailNewsUrl::SetUrlState (this=0x7f00896f7be8, 
    aRunningUrl=<optimized out>, aExitCode=0)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/base/util/nsMsgMailNewsUrl.cpp:109
#19 0x00007f00b91a3b3d in nsSmtpProtocol::ProcessProtocolState (
    this=0x7f008bbe6000, url=<optimized out>, inputStream=0x7f008b15d010, 
    sourceOffset=<optimized out>, length=48)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/compose/src/nsSmtpProtocol.cpp:1949
#20 0x00007f00b90fbecf in nsMsgProtocol::OnDataAvailable (this=0x7f008bbe6000, 
    request=<optimized out>, ctxt=<optimized out>, inStr=0x7f008b15d010, 
    sourceOffset=621, count=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mailnews/base/util/nsMsgProtocol.cpp:389
#21 0x00007f00b87eda63 in nsInputStreamPump::OnStateTransfer (
    this=0x7f009c234860)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/netwerk/base/src/nsInputStreamPump.cpp:512
#22 0x00007f00b87edbcf in nsInputStreamPump::OnInputStreamReady (
    this=0x7f009c234860, stream=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/netwerk/base/src/nsInputStreamPump.cpp:402
#23 0x00007f00b9398b74 in nsInputStreamReadyEvent::Run (this=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/xpcom/io/nsStreamUtils.cpp:114
#24 0x00007f00b93a713f in nsThread::ProcessNextEvent (this=0x7f00ba550f50, 
    mayWait=false, result=0x7fff61c4445f)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/xpcom/threads/nsThread.cpp:660
#25 0x00007f00b937bebd in NS_ProcessNextEvent_P (thread=<optimized out>, 
    mayWait=false)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/obj-x86_64-linux-gnu/mozilla/xpcom/build/nsThreadUtils.cpp:245
#26 0x00007f00b9319d2e in mozilla::ipc::MessagePump::Run (this=0x7f00ad016d40, 
    aDelegate=0x7f00ba5d0760)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/ipc/glue/MessagePump.cpp:110
#27 0x00007f00b93c53b1 in RunHandler (this=0x7f00ba5d0760)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/ipc/chromium/src/base/message_loop.cc:201
#28 MessageLoop::Run (this=0x7f00ba5d0760)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/ipc/chromium/src/base/message_loop.cc:175
#29 0x00007f00b9056f76 in nsBaseAppShell::Run (this=0x7f00aad81a90)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/widget/src/xpwidgets/nsBaseAppShell.cpp:189
#30 0x00007f00b8f2a960 in nsAppStartup::Run (this=0x7f00aac6b3d0)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/toolkit/components/startup/nsAppStartup.cpp:220
#31 0x00007f00b87d1168 in XRE_main (argc=<optimized out>, 
    argv=<optimized out>, aAppData=<optimized out>)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mozilla/toolkit/xre/nsAppRunner.cpp:3519
#32 0x0000000000401c97 in do_main (argv=0x7fff61c45f68, argc=1, 
    exePath=0x7fff61c44e58 "/usr/lib/thunderbird-11.0/libxpcom.so")
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mail/app/nsMailApp.cpp:143
#33 main (argc=1, argv=0x7fff61c45f68)
    at /build/buildd/thunderbird-11.0+build1/build-tree/mozilla/mail/app/nsMailApp.cpp:226

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: thunderbird 11.0+build1-0ubuntu0.11.10.1
ProcVersionSignature: Ubuntu 3.0.0-16.29-generic 3.0.20
Uname: Linux 3.0.0-16-generic x86_64
AddonCompatCheckDisabled: False
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: I82801AAICH [Intel 82801AA-ICH], device 0: Intel ICH [Intel 82801AA-ICH]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
AudioDevicesInUse:
 USER        PID ACCESS COMMAND
 /dev/snd/controlC0:  blair      1675 F.... pulseaudio
BuildID: 20120310043956
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'I82801AAICH'/'Intel 82801AA-ICH with STAC9700,83,84 at irq 21'
   Mixer name	: 'SigmaTel STAC9700,83,84'
   Components	: 'AC97a:83847600'
   Controls      : 34
   Simple ctrls  : 24
Channel: release
Date: Thu Mar 22 15:46:03 2012
ExecutablePath: /usr/lib/thunderbird-11.0/thunderbird-bin
ForcedLayersAccel: False
IfupdownConfig:
 auto lo
 iface lo inet loopback
IncompatibleExtensions:
 Messaging Menu and Unity Launcher integration - <email address hidden>, Version=0.8.3, minVersion=3.3a1pre, maxVersion=11.0a1, Location=app-global, Type=extension, Active=Yes
 EDS Contact Integration - <email address hidden>, Version=0.3.9, minVersion=7.0, maxVersion=11.0a1, Location=app-global, Type=extension, Active=Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64+mac (20111012)
IwConfig:
 lo        no wireless extensions.
 
 eth0      no wireless extensions.
 
 tun0      no wireless extensions.
Plugins:
 Gnome Shell Integration - Lib=libgnome-shell-browser-plugin.so, Location=/usr/lib/mozilla/plugins
 VLC Multimedia Plugin (compatible Totem 3.0.1) - Lib=libtotem-cone-plugin.so, Location=/usr/lib/mozilla/plugins
 QuickTime Plug-in 7.6.6 - Lib=libtotem-narrowspace-plugin.so, Location=/usr/lib/mozilla/plugins
 Windows Media Player Plug-in 10 (compatible; Totem) - Lib=libtotem-gmp-plugin.so, Location=/usr/lib/mozilla/plugins
 DivX® Web Player - Lib=libtotem-mully-plugin.so, Location=/usr/lib/mozilla/plugins
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Profiles: Profile0 (Default) - LastVersion=11.0/20120310043956 (Running)
RfKill:
 
RunningIncompatibleAddons: True
SourcePackage: thunderbird
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/01/2006
dmi.bios.vendor: innotek GmbH
dmi.bios.version: VirtualBox
dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:
dmi.product.name: VirtualBox
dmi.product.version: 1.2
dmi.sys.vendor: innotek GmbH