Version:           2.1.3 (using KDE KDE 3.5.5)
Installed from:    Fedora RPMs
OS:                Linux

I left ktorrent running overnight and woke up to this lovely message:

[Thread debugging using libthread_db enabled]
[New Thread -1209166128 (LWP 31183)]
[New Thread -1225036912 (LWP 31678)]
[New Thread -1214547056 (LWP 31677)]
[KCrash handler]
#6  0x0066297b in dht::ParseRsp () from /usr/lib/libktorrent-2.1.3.so
#7  0x00663932 in dht::MakeRPCMsg () from /usr/lib/libktorrent-2.1.3.so
#8  0x00663aa2 in dht::RPCServer::readPacket ()
   from /usr/lib/libktorrent-2.1.3.so
#9  0x00663dc2 in dht::RPCServer::qt_invoke ()
   from /usr/lib/libktorrent-2.1.3.so
#10 0x06750bea in QObject::activate_signal ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#11 0x0675171d in QObject::activate_signal ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#12 0x06fe52cc in KNetwork::KClientSocketBase::readyRead ()
   from /usr/lib/libkdecore.so.4
#13 0x06fe5306 in KNetwork::KClientSocketBase::slotReadActivity ()
   from /usr/lib/libkdecore.so.4
#14 0x06ff79e3 in KNetwork::KClientSocketBase::qt_invoke ()
   from /usr/lib/libkdecore.so.4
#15 0x06ff7a86 in KNetwork::KDatagramSocket::qt_invoke ()
   from /usr/lib/libkdecore.so.4
#16 0x06750bea in QObject::activate_signal ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#17 0x067515c2 in QObject::activate_signal ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#18 0x06add910 in QSocketNotifier::activated ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#19 0x067717d0 in QSocketNotifier::event ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#20 0x066e7e6b in QApplication::internalNotify ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#21 0x066e92e9 in QApplication::notify ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#22 0x06f961e2 in KApplication::notify () from /usr/lib/libkdecore.so.4
#23 0x066db631 in QEventLoop::activateSocketNotifiers ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#24 0x066901c1 in QEventLoop::processEvents ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#25 0x067013f0 in QEventLoop::enterLoop ()
   from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#26 0x067012a6 in QEventLoop::exec () from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#27 0x066e797f in QApplication::exec () from /usr/lib/qt-3.3/lib/libqt-mt.so.3
#28 0x0806f617 in QWidget::setUpdatesEnabled ()
#29 0x00125f2c in __libc_start_main () from /lib/libc.so.6
#30 0x080627a1 in QWidget::setUpdatesEnabled ()


The last two lines in the log are:
Wed May 9 23:32:12 2007: Retransmitting 1879:196608
Wed May 9 23:32:12 2007: Retransmitting 1879:212992

I have no idea when exactly it crashed though. It has been doing these random crashes for quite some time.