Backtrace of crash after renaming a parent folder with child folders:
========================================================================

[Thread debugging using libthread_db enabled]
[New Thread 0xb5e339e0 (LWP 6606)]
[New Thread 0xb344db90 (LWP 6644)]
[New Thread 0xb3c4eb90 (LWP 6643)]
[New Thread 0xb444fb90 (LWP 6642)]
[New Thread 0xb4c50b90 (LWP 6641)]
[KCrash handler]
#6  0xb7267705 in QGArray::resize (this=0x8cd7858, newsize=0, optim=MemOptim)
    at tools/qgarray.cpp:245
#7  0xb726780a in QGArray::resize (this=0x8cd7858, newsize=0)
    at tools/qgarray.cpp:302
#8  0xb4fea487 in QMemArray<KMMsgDictEntry*>::resize (this=0x8cd7858, size=0)
    at /usr/share/qt3/include/qmemarray.h:73
#9  0xb4fea55a in ~KMMsgDictREntry (this=0x8cd7858) at kmmsgdict.cpp:85
#10 0xb4fe8246 in KMMsgDict::deleteRentry (entry=0x8cd7858)
    at kmmsgdict.cpp:193
#11 0xb4fed373 in FolderStorage::setRDict (this=0x8d87c58, rentry=0x0)
    at folderstorage.cpp:1025
#12 0xb4fe84e0 in KMMsgDict::removeFolderIds (this=0x84b1280, 
    storage=@0x8d87c58) at kmmsgdict.cpp:648
#13 0xb4fee14b in FolderStorage::remove (this=0x8d87c58)
    at folderstorage.cpp:750
#14 0xb507ead8 in KMFolderImap::remove (this=0x8d87c58)
    at kmfolderimap.cpp:235
#15 0xb4fcde90 in KMFolder::remove (this=0x8dac7b0) at kmfolder.cpp:519
#16 0xb50101c5 in KMFolderMgr::removeFolder (this=0x84c3498, 
    aFolder=0x8dac7b0) at kmfoldermgr.cpp:366
#17 0xb501029b in KMFolderMgr::remove (this=0x84c3498, aFolder=0x8dac7b0)
    at kmfoldermgr.cpp:359
#18 0xb507af39 in KMFolderImap::checkFolders (this=0x8531f00, 
    subfolderNames=@0x8dcfaa0, myNamespace=@0x8d436f0) at kmfolderimap.cpp:989
#19 0xb507b6c4 in KMFolderImap::slotListResult (this=0x8531f00, 
    subfolderNames=@0x8dcfaa0, subfolderPaths=@0x8dcfaa4, 
    subfolderMimeTypes=@0x8dcfaa8, subfolderAttributes=@0x8dcfaac, 
    jobData=@0x8d436e8) at kmfolderimap.cpp:820
#20 0xb507e5d2 in KMFolderImap::qt_invoke (this=0x8531f00, _id=21, 
    _o=0xbfc63214) at kmfolderimap.moc:334
#21 0xb6f72704 in QObject::activate_signal (this=0x8dcfa28, clist=0x808af18, 
    o=0xbfc63214) at kernel/qobject.cpp:2359
#22 0xb4fa2bf0 in KMail::ListJob::receivedFolders (this=0x8dcfa28, 
    t0=@0x8dcfaa0, t1=@0x8dcfaa4, t2=@0x8dcfaa8, t3=@0x8dcfaac, t4=@0x8d436e8)
    at listjob.moc:122
#23 0xb4fa33fe in KMail::ListJob::slotListResult (this=0x8dcfa28, 
    job=0x8412ff0) at listjob.cpp:183
#24 0xb4fa3516 in KMail::ListJob::qt_invoke (this=0x8dcfa28, _id=2, 
    _o=0xbfc63384) at listjob.moc:128
#25 0xb6f72704 in QObject::activate_signal (this=0x8412ff0, clist=0x8d9fed8, 
    o=0xbfc63384) at kernel/qobject.cpp:2359
#26 0xb6a257de in KIO::Job::result (this=0x8412ff0, t0=0x8412ff0)
    at ./jobclasses.moc:162
#27 0xb6a6b9dd in KIO::Job::emitResult (this=0x8412ff0)
    at /build/buildd/kdelibs-3.5.9/./kio/kio/job.cpp:235
#28 0xb6a6bb4e in KIO::SimpleJob::slotFinished (this=0x8412ff0)
    at /build/buildd/kdelibs-3.5.9/./kio/kio/job.cpp:601
#29 0xb6a6bea3 in KIO::ListJob::slotFinished (this=0x8412ff0)
    at /build/buildd/kdelibs-3.5.9/./kio/kio/job.cpp:2129
#30 0xb6a80705 in KIO::ListJob::qt_invoke (this=0x8412ff0, _id=16, 
    _o=0xbfc63618) at ./jobclasses.moc:1768
#31 0xb6f72704 in QObject::activate_signal (this=0x86740a0, clist=0x86d1a80, 
    o=0xbfc63618) at kernel/qobject.cpp:2359
#32 0xb6f731e9 in QObject::activate_signal (this=0x86740a0, signal=6)
    at kernel/qobject.cpp:2328
#33 0xb6a1ddac in KIO::SlaveInterface::finished (this=0x86740a0)
    at ./slaveinterface.moc:226
#34 0xb6a6a9a9 in KIO::SlaveInterface::dispatch (this=0x86740a0, _cmd=104, 
    rawdata=@0xbfc637f0)
    at /build/buildd/kdelibs-3.5.9/./kio/kio/slaveinterface.cpp:243
#35 0xb6a8ce4a in KIO::SlaveInterface::dispatch (this=0x86740a0)
    at /build/buildd/kdelibs-3.5.9/./kio/kio/slaveinterface.cpp:173
#36 0xb6a33d7c in KIO::Slave::gotInput (this=0x86740a0)
    at /build/buildd/kdelibs-3.5.9/./kio/kio/slave.cpp:300
#37 0xb6a62278 in KIO::Slave::qt_invoke (this=0x86740a0, _id=4, _o=0xbfc638f0)
    at ./slave.moc:113
#38 0xb6f72704 in QObject::activate_signal (this=0x8673a20, clist=0x8674338, 
    o=0xbfc638f0) at kernel/qobject.cpp:2359
#39 0xb6f73051 in QObject::activate_signal (this=0x8673a20, signal=2, 
    param=29) at kernel/qobject.cpp:2452
#40 0xb7302b99 in QSocketNotifier::activated (this=0x8673a20, t0=29)
    at .moc/debug-shared-mt/moc_qsocketnotifier.cpp:85
#41 0xb6f94766 in QSocketNotifier::event (this=0x8673a20, e=0xbfc63c00)
    at kernel/qsocketnotifier.cpp:261
#42 0xb6f06c36 in QApplication::internalNotify (this=0xbfc63eac, 
    receiver=0x8673a20, e=0xbfc63c00) at kernel/qapplication.cpp:2638
#43 0xb6f08a5f in QApplication::notify (this=0xbfc63eac, receiver=0x8673a20, 
    e=0xbfc63c00) at kernel/qapplication.cpp:2361
#44 0xb763f672 in KApplication::notify (this=0xbfc63eac, receiver=0x8673a20, 
    event=0xbfc63c00)
    at /build/buildd/kdelibs-3.5.9/./kdecore/kapplication.cpp:550
#45 0xb6e9728d in QApplication::sendEvent (receiver=0x8673a20, 
    event=0xbfc63c00) at ../include/qapplication.h:523
#46 0xb6ef8b4a in QEventLoop::activateSocketNotifiers (this=0x80b7508)
    at kernel/qeventloop_unix.cpp:581
#47 0xb6eac630 in QEventLoop::processEvents (this=0x80b7508, flags=4)
    at kernel/qeventloop_x11.cpp:386
#48 0xb6f21f90 in QEventLoop::enterLoop (this=0x80b7508)
    at kernel/qeventloop.cpp:201
#49 0xb6f21c8e in QEventLoop::exec (this=0x80b7508)
    at kernel/qeventloop.cpp:148
#50 0xb6f087df in QApplication::exec (this=0xbfc63eac)
    at kernel/qapplication.cpp:2761
#51 0x0805f8ff in main (argc=) at main.cpp:188