Version:           1.9.7 (using KDE 3.5.7, Kubuntu (feisty) 4:3.5.7-0ubuntu1~feisty2)
Compiler:          Target: i486-linux-gnu
OS:                Linux (i686) release 2.6.20-16-generic

I created some new folders using outlook, specifically "!To Reply" and "@Actions" which didn't show up in the cached IMAP account when I checked my mail next. Rebuilding the index didn't help, and attempting to rebuild the cache crashes kmail, repeatably, with the following backtrace.

Unfortunately I can't tell which folder it is crashing on.

Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread -1250384176 (LWP 15015)]
[New Thread -1281647728 (LWP 15020)]
[New Thread -1273255024 (LWP 15019)]
[New Thread -1264862320 (LWP 15018)]
[New Thread -1256469616 (LWP 15017)]
[KCrash handler]
#6  0x00000000 in ?? ()
#7  0xb7bed920 in KMail::MessageProperty::filtering (msgBase=0x8752d98)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/messageproperty.cpp:59
#8  0xb7dc7ad5 in KMFilterMgr::beginFiltering (this=0x85d3bd8, 
    msgBase=0x8752d98)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/kmfiltermgr.cpp:151
#9  0xb7dd4646 in KMFilterMgr::process (this=0x85d3bd8, msg=0x8752d98, 
    set=KMFilterMgr::Inbound, account=true, accountId=1070924066)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/kmfiltermgr.cpp:295
#10 0xb7dd4ed2 in KMAccount::processNewMsg (this=0x8390390, aMsg=0x8752d98)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/kmaccount.cpp:232
#11 0xb7e4a6f0 in KMFolderCachedImap::addMsgInternal (this=0x838e618, 
    msg=0x8752d98, newMail=true, index_return=0xbfa4e618)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/kmfoldercachedimap.cpp:446
#12 0xb7e6216d in KMail::CachedImapJob::slotGetNextMessage (this=0x8739ea8, 
    job=0x874e8c8)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/cachedimapjob.cpp:282
#13 0xb7d86992 in KMail::CachedImapJob::qt_invoke (this=0x8739ea8, _id=3, 
    _o=0xbfa4e6f4) at ./cachedimapjob.moc:154
#14 0xb707888b in QObject::activate_signal (this=0x874e8c8, clist=0x8a93be0, 
    o=0xbfa4e6f4) at kernel/qobject.cpp:2356
#15 0xb5c21eee in KIO::Job::result (this=0x874e8c8, t0=0x874e8c8)
    at ./jobclasses.moc:162
#16 0xb5c63bad in KIO::Job::emitResult (this=0x874e8c8)
    at /root/kdelibs/kdelibs-3.5.7/./kio/kio/job.cpp:235
#17 0xb5c6fe3e in KIO::SimpleJob::slotFinished (this=0x874e8c8)
    at /root/kdelibs/kdelibs-3.5.7/./kio/kio/job.cpp:601
#18 0xb5c7054d in KIO::TransferJob::slotFinished (this=0x874e8c8)
    at /root/kdelibs/kdelibs-3.5.7/./kio/kio/job.cpp:971
#19 0xb5c637da in KIO::TransferJob::qt_invoke (this=0x874e8c8, _id=17, 
    _o=0xbfa4ea5c) at ./jobclasses.moc:1071
#20 0xb707888b in QObject::activate_signal (this=0x8705e38, clist=0x883e978, 
    o=0xbfa4ea5c) at kernel/qobject.cpp:2356
#21 0xb7079330 in QObject::activate_signal (this=0x8705e38, signal=6)
    at kernel/qobject.cpp:2325
#22 0xb5c1d87c in KIO::SlaveInterface::finished (this=0x8705e38)
    at ./slaveinterface.moc:226
#23 0xb5c8de50 in KIO::SlaveInterface::dispatch (this=0x8705e38, _cmd=104, 
    rawdata=@0xbfa4ec70)
    at /root/kdelibs/kdelibs-3.5.7/./kio/kio/slaveinterface.cpp:243
#24 0xb5c8ce4a in KIO::SlaveInterface::dispatch (this=0x8705e38)
    at /root/kdelibs/kdelibs-3.5.7/./kio/kio/slaveinterface.cpp:173
#25 0xb5c3311c in KIO::Slave::gotInput (this=0x8705e38)
    at /root/kdelibs/kdelibs-3.5.7/./kio/kio/slave.cpp:300
#26 0xb5c7d000 in KIO::Slave::qt_invoke (this=0x8705e38, _id=4, _o=0xbfa4ed98)
    at ./slave.moc:113
#27 0xb707888b in QObject::activate_signal (this=0x8704fe0, clist=0x8706440, 
    o=0xbfa4ed98) at kernel/qobject.cpp:2356
#28 0xb70791a2 in QObject::activate_signal (this=0x8704fe0, signal=2, 
    param=14) at kernel/qobject.cpp:2449
#29 0xb7405877 in QSocketNotifier::activated (this=0x8704fe0, t0=14)
    at .moc/debug-shared-mt/moc_qsocketnotifier.cpp:85
#30 0xb709b44a in QSocketNotifier::event (this=0x8704fe0, e=0xbfa4f0c8)
    at kernel/qsocketnotifier.cpp:258
#31 0xb700fa60 in QApplication::internalNotify (this=0xbfa4f444, 
    receiver=0x8704fe0, e=0xbfa4f0c8) at kernel/qapplication.cpp:2635
#32 0xb701188f in QApplication::notify (this=0xbfa4f444, receiver=0x8704fe0, 
    e=0xbfa4f0c8) at kernel/qapplication.cpp:2358
#33 0xb774bc32 in KApplication::notify (this=0xbfa4f444, receiver=0x8704fe0, 
    event=0xbfa4f0c8)
    at /root/kdelibs/kdelibs-3.5.7/./kdecore/kapplication.cpp:550
#34 0xb6fa21e9 in QApplication::sendEvent (receiver=0x8704fe0, 
    event=0xbfa4f0c8) at ../include/qapplication.h:520
#35 0xb7001e59 in QEventLoop::activateSocketNotifiers (this=0x808bba0)
    at kernel/qeventloop_unix.cpp:578
#36 0xb6fb6d07 in QEventLoop::processEvents (this=0x808bba0, flags=4)
    at kernel/qeventloop_x11.cpp:383
#37 0xb702a136 in QEventLoop::enterLoop (this=0x808bba0)
    at kernel/qeventloop.cpp:198
#38 0xb7029f46 in QEventLoop::exec (this=0x808bba0)
    at kernel/qeventloop.cpp:145
#39 0xb7011609 in QApplication::exec (this=0xbfa4f444)
    at kernel/qapplication.cpp:2758
#40 0x0804a2de in main (argc=-1208506808, argv=0x8584ca0)
    at /root/kdepim/new/kdepim-3.5.7/./kmail/main.cpp:110
#41 0xb77e5ebc in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#42 0x0804a041 in _start ()