Application that crashed: kontact
Version of the application: 4.3.1
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.3
Operating System: Linux 2.6.30-2-amd64 x86_64
Distribution: Debian GNU/Linux testing (squeeze)

What I was doing when the application crashed:
when creating a new email, replying to or forwarding I noticed kmail crashes unpon completing the To: filed.
My address book is set up to use OpenLDAP. Usually when I type (even addresses that I never sent to before) it auto completes or displays names base on what is being typed. 
Sometimes when typing the address (format is fistname.lastname@blablabla) it does not complete/find the name in the address book and krashes. It never happened beforethat upgrade, at least on my michine. 

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#5  0x00007f71eaa4152f in KPIM::AddresseeLineEdit::slotLDAPSearchData(QList<KPIM::LdapResult> const&) () from /usr/lib/libkdepim.so.4
#6  0x00007f71eaa4251c in KPIM::AddresseeLineEdit::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdepim.so.4
#7  0x00007f71d3a0e3ed in ?? () from /usr/lib/libkmailprivate.so.4
#8  0x00007f71d3a7db7d in ?? () from /usr/lib/libkmailprivate.so.4
#9  0x00007f71e9c16df2 in QMetaObject::activate (sender=0x3b90970, from_signal_index=<value optimized out>, to_signal_index=5, argv=0x1) at kernel/qobject.cpp:3112
#10 0x00007f71eaa45275 in KPIM::LdapSearch::searchData(QList<KPIM::LdapResult> const&) () from /usr/lib/libkdepim.so.4
#11 0x00007f71eaa483e1 in KPIM::LdapSearch::slotDataTimer() () from /usr/lib/libkdepim.so.4
#12 0x00007f71eaa48465 in KPIM::LdapSearch::finish() () from /usr/lib/libkdepim.so.4
#13 0x00007f71eaa4ad88 in KPIM::LdapSearch::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdepim.so.4
#14 0x00007f71e9c16df2 in QMetaObject::activate (sender=0x3b8ccf0, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x1) at kernel/qobject.cpp:3112
#15 0x00007f71eaa45969 in KPIM::LdapClient::slotDone() () from /usr/lib/libkdepim.so.4
#16 0x00007f71eaa4b4d8 in KPIM::LdapClient::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkdepim.so.4
#17 0x00007f71e9c16df2 in QMetaObject::activate (sender=0x3ff4a20, from_signal_index=<value optimized out>, to_signal_index=7, argv=0x1) at kernel/qobject.cpp:3112
#18 0x00007f71e9feee52 in KJob::result(KJob*) () from /usr/lib/libkdecore.so.5
#19 0x00007f71e9fef1cf in KJob::emitResult() () from /usr/lib/libkdecore.so.5
#20 0x00007f71e7477ec0 in KIO::SimpleJob::slotFinished() () from /usr/lib/libkio.so.5
#21 0x00007f71e7478383 in KIO::TransferJob::slotFinished() () from /usr/lib/libkio.so.5
#22 0x00007f71e747309d in KIO::TransferJob::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkio.so.5
#23 0x00007f71e9c16df2 in QMetaObject::activate (sender=0x3cd8bb0, from_signal_index=<value optimized out>, to_signal_index=8, argv=0x1) at kernel/qobject.cpp:3112
#24 0x00007f71e7535021 in KIO::SlaveInterface::dispatch(int, QByteArray const&) () from /usr/lib/libkio.so.5
#25 0x00007f71e7531ab2 in KIO::SlaveInterface::dispatch() () from /usr/lib/libkio.so.5
#26 0x00007f71e752451e in KIO::Slave::gotInput() () from /usr/lib/libkio.so.5
#27 0x00007f71e7526848 in KIO::Slave::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkio.so.5
#28 0x00007f71e9c16df2 in QMetaObject::activate (sender=0x3792da0, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x1) at kernel/qobject.cpp:3112
#29 0x00007f71e7440d91 in ?? () from /usr/lib/libkio.so.5
#30 0x00007f71e74411ea in KIO::Connection::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkio.so.5
#31 0x00007f71e9c116c8 in QObject::event (this=0x3792da0, e=0x3fb23a0) at kernel/qobject.cpp:1110
#32 0x00007f71e907b01d in QApplicationPrivate::notify_helper (this=0x1bc6540, receiver=0x3792da0, e=0x3fb23a0) at kernel/qapplication.cpp:4065
#33 0x00007f71e908307a in QApplication::notify (this=0x7fff18a9fe30, receiver=0x3792da0, e=0x3fb23a0) at kernel/qapplication.cpp:4030
#34 0x00007f71ea5a10db in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#35 0x00007f71e9c01c9c in QCoreApplication::notifyInternal (this=0x7fff18a9fe30, receiver=0x3792da0, event=0x3fb23a0) at kernel/qcoreapplication.cpp:610
#36 0x00007f71e9c028e4 in QCoreApplication::sendEvent (receiver=0x0, event_type=0, data=0x1b93340) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#37 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x1b93340) at kernel/qcoreapplication.cpp:1247
#38 0x00007f71e9c2a7d3 in QCoreApplication::sendPostedEvents (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#39 postEventSourceDispatch (s=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:276
#40 0x00007f71e2d3212a in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#41 0x00007f71e2d35988 in ?? () from /lib/libglib-2.0.so.0
#42 0x00007f71e2d35b3c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#43 0x00007f71e9c2a39c in QEventDispatcherGlib::processEvents (this=0x1b92f70, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:407
#44 0x00007f71e9111f1f in QGuiEventDispatcherGlib::processEvents (this=0x4d08550, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#45 0x00007f71e9c00562 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#46 0x00007f71e9c00934 in QEventLoop::exec (this=0x7fff18a9fc90, flags=...) at kernel/qeventloop.cpp:201
#47 0x00007f71e9c02ba4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#48 0x0000000000404751 in _start ()

Reported using DrKonqi