Version:           KMail: 1.9.6 (using KDE KDE 3.5.6)
Installed from:    Compiled From Sources
Compiler:          gcc (GCC) 4.1.2 (Gentoo 4.1.2)
 CFLAGS="-O2 -march=pentium-m -pipe -ggdb"
OS:                Linux

Cannot reproduce the bug. Happened two times the last three days.

Using host libthread_db library "/lib/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread -1241798336 (LWP 20450)]
[New Thread -1282266224 (LWP 20455)]
[New Thread -1273873520 (LWP 20454)]
[New Thread -1265480816 (LWP 20453)]
[New Thread -1257088112 (LWP 20452)]
[KCrash handler]
#6  0x50414d49 in ?? ()
#7  0xb56180b0 in KMail::ImapJob::slotGetNextMessage (this=0x859fae8)
    at imapjob.cpp:279
#8  0xb5620d19 in KMail::ImapJob::init (this=0x859fae8, 
    jt=KMail::FolderJob::tGetMessage, sets=@0xbfc27138, folder=0x0, 
    msgList=@0x859fb10) at imapjob.cpp:216
#9  0xb56221eb in KMail::ImapJob::execute (this=0x859fae8) at imapjob.cpp:647
#10 0xb535fc7d in KMail::FolderJob::start (this=0xb60e4150)
    at folderjob.cpp:109
#11 0xb553720d in KMMainWidget::slotMsgSelected (this=0x8341ca0, 
    msg=0x89328b8) at kmmainwidget.cpp:2037
#12 0xb5648e9e in KMMainWidget::qt_invoke (this=0x8341ca0, _id=54, 
    _o=0xbfc27244) at kmmainwidget.moc:507
#13 0xb6876589 in QObject::activate_signal (this=0x83df7b8, clist=0x82783f0, 
    o=0xbfc27244) at kernel/qobject.cpp:2356
#14 0xb539edde in KMHeaders::selected (this=0x83df7b8, t0=0x89328b8)
    at kmheaders.moc:250
#15 0xb54a1453 in KMHeaders::highlightMessage (this=0x83df7b8, lvi=0x890e890, 
    markitread=false) at kmheaders.cpp:2033
#16 0xb54a182a in KMHeaders::highlightMessage (this=0x83df7b8, i=0x890e890)
    at kmheaders.cpp:2282
#17 0xb55f5bb6 in KMHeaders::qt_invoke (this=0x83df7b8, _id=106, 
    _o=0xbfc27384) at kmheaders.moc:295
#18 0xb6876589 in QObject::activate_signal (this=0x83df7b8, clist=0x83fe440, 
    o=0xbfc27384) at kernel/qobject.cpp:2356
#19 0xb6bc4681 in QListView::currentChanged (this=0x83df7b8, t0=0x890e890)
    at .moc/release-shared-mt/moc_qlistview.cpp:328
#20 0xb6957d1e in QListView::setCurrentItem (this=0x83df7b8, i=0x890e890)
    at widgets/qlistview.cpp:5477
#21 0xb695a9cc in QListView::contentsMousePressEventEx (this=0x83df7b8, 
    e=0xbfc276b4) at widgets/qlistview.cpp:4353
#22 0xb695b484 in QListView::contentsMousePressEvent (this=0x83df7b8, 
    e=0xbfc276b4) at widgets/qlistview.cpp:4237
#23 0xb71612fa in KListView::contentsMousePressEvent (this=0x83df7b8, 
    e=0xbfc276b4) at klistview.cpp:805
#24 0xb54a1952 in KMHeaders::contentsMousePressEvent (this=0x83df7b8, 
    e=0xbfc276b4) at kmheaders.cpp:2194
#25 0xb698d91f in QScrollView::viewportMousePressEvent (this=0x83df7b8, 
    e=0xbfc27b5c) at widgets/qscrollview.cpp:1733
#26 0xb698ac29 in QScrollView::eventFilter (this=0x83df7b8, obj=0x83e0160, 
    e=0xbfc27b5c) at widgets/qscrollview.cpp:1496
#27 0xb6958b66 in QListView::eventFilter (this=0x83df7b8, o=0x83e0160, 
    e=0xbfc27b5c) at widgets/qlistview.cpp:3867
#28 0xb54a3749 in KMHeaders::eventFilter (this=0x83df7b8, o=0x83e0160, 
    e=0xbfc27b5c) at kmheaders.cpp:244
#29 0xb6875e86 in QObject::activate_filters (this=0x83e0160, e=0xbfc27b5c)
    at kernel/qobject.cpp:903
#30 0xb6875eeb in QObject::event (this=0x83e0160, e=0xbfc27b5c)
    at kernel/qobject.cpp:735
#31 0xb68afa3c in QWidget::event (this=0x83e0160, e=0xbfc27b5c)
    at kernel/qwidget.cpp:4659
#32 0xb6816f97 in QApplication::internalNotify (this=0xbfc27fe8, 
    receiver=0x83e0160, e=0xbfc27b5c) at kernel/qapplication.cpp:2635
#33 0xb6817d78 in QApplication::notify (this=0xbfc27fe8, receiver=0x83e0160, 
    e=0xbfc27b5c) at kernel/qapplication.cpp:2421
#34 0xb6f7139e in KApplication::notify (this=0xbfc27fe8, receiver=0x83e0160, 
    event=0xbfc27b5c) at kapplication.cpp:550
#35 0xb67b70c2 in QETWidget::translateMouseEvent (this=0x83e0160, 
    event=0xbfc27ef8) at kernel/qapplication.h:499
#36 0xb67b69a0 in QApplication::x11ProcessEvent (this=0xbfc27fe8, 
    event=0xbfc27ef8) at kernel/qapplication_x11.cpp:3449
#37 0xb67c6a81 in QEventLoop::processEvents (this=0x8099a68, 
    flags=<value optimized out>) at kernel/qeventloop_x11.cpp:192
#38 0xb682db01 in QEventLoop::enterLoop (this=0x8099a68)
    at kernel/qeventloop.cpp:198
#39 0xb682d986 in QEventLoop::exec (this=0x8099a68)
    at kernel/qeventloop.cpp:145
#40 0xb6816a1f in QApplication::exec (this=0xbfc27fe8)
    at kernel/qapplication.cpp:2758
#41 0x080611f6 in main (argc=143861944, argv=0x0) at main.cpp:163
#42 0xb5fd4838 in __libc_start_main (main=0x8060cc0 <main>, argc=1, 
    ubp_av=0xbfc281f4, init=0x8065720 <__libc_csu_init>, 
    fini=0x8065710 <__libc_csu_fini>, rtld_fini=0xb7feefd0 <_dl_fini>, 
    stack_end=0xbfc281ec) at libc-start.c:238
#43 0x08058601 in _start ()