Version:           0.12.3 (using KDE 3.5.5, Kubuntu (dapper) 4:3.5.5-0ubuntu1~dapper2)
Compiler:          Target: i486-linux-gnu
OS:                Linux (i686) release 2.6.15-23-386

Welcome!
My Kopete 0.12.3 from official kubuntu package regullary crashes (SIGSEGV) without visible reasons. My computer is running non-stop now, so I can't always see when it happens. I suppose, that it's related to auto reconnect after disconnect, but now i saw the crash, and don't saw disconnection (mabe it was, but Kopete don't notify...). I use only history plugin, and my accounts are: yahoo, MSN, jabber with gadu-gadu transport and gadu-gadu (native), but the last acconut wasn't in use while crashing.
Before this crash, when I saw "Kopete crash" dialog, I can also see pop-ups with information from PSI, that servers break connection, so there will be problem with connection (so my sugestion above), but this time it wouldn't be.

This is my bugtrace:
(no debugging symbols found)
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread -1240914240 (LWP 21280)]
(no debugging symbols found)

[KCrash handler]
#6  0xb6bba415 in QString::QString () from /usr/lib/libqt-mt.so.3
#7  0xb7e74b3a in Kopete::Group::displayName () from /usr/lib/libkopete.so.1
#8  0xb578f2d6 in JabberBaseContact::updateContact ()
   from /usr/lib/kde3/kopete_jabber.so
#9  0xb57a3e0f in JabberContactPool::addContact ()
   from /usr/lib/kde3/kopete_jabber.so
#10 0xb57872c3 in JabberAccount::slotContactUpdated ()
   from /usr/lib/kde3/kopete_jabber.so
#11 0xb578af6b in JabberAccount::qt_invoke ()
   from /usr/lib/kde3/kopete_jabber.so
#12 0xb689f051 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#13 0xb587f857 in JabberClient::contactUpdated ()
   from /usr/lib/kde3/kopete_jabber.so
#14 0xb587f8a2 in JabberClient::slotContactUpdated ()
   from /usr/lib/kde3/kopete_jabber.so
#15 0xb5882819 in JabberClient::qt_invoke ()
   from /usr/lib/kde3/kopete_jabber.so
#16 0xb689f051 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#17 0xb57e6a21 in XMPP::Client::rosterItemUpdated ()
   from /usr/lib/kde3/kopete_jabber.so
#18 0xb5830214 in XMPP::Client::importRosterItem ()
   from /usr/lib/kde3/kopete_jabber.so
#19 0xb583063c in XMPP::Client::importRoster ()
   from /usr/lib/kde3/kopete_jabber.so
#20 0xb58307e6 in XMPP::Client::prRoster ()
   from /usr/lib/kde3/kopete_jabber.so
#21 0xb57e660b in XMPP::Client::qt_invoke ()
   from /usr/lib/kde3/kopete_jabber.so
#22 0xb689f051 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#23 0xb586366e in XMPP::JT_PushRoster::roster ()
   from /usr/lib/kde3/kopete_jabber.so
#24 0xb584bf0b in XMPP::JT_PushRoster::take ()
   from /usr/lib/kde3/kopete_jabber.so
#25 0xb5829325 in XMPP::Task::take () from /usr/lib/kde3/kopete_jabber.so
#26 0xb582be91 in XMPP::Client::distribute ()
   from /usr/lib/kde3/kopete_jabber.so
#27 0xb582c109 in XMPP::Client::streamReadyRead ()
   from /usr/lib/kde3/kopete_jabber.so
#28 0xb57e654c in XMPP::Client::qt_invoke ()
   from /usr/lib/kde3/kopete_jabber.so
#29 0xb689f051 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#30 0xb689faec in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#31 0xb57e4f5a in XMPP::Stream::readyRead ()
   from /usr/lib/kde3/kopete_jabber.so
#32 0xb5818f55 in XMPP::ClientStream::doReadyRead ()
   from /usr/lib/kde3/kopete_jabber.so
#33 0xb57e54f0 in XMPP::ClientStream::qt_invoke ()
   from /usr/lib/kde3/kopete_jabber.so
#34 0xb689f051 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#35 0xb6c32432 in QSignal::signal () from /usr/lib/libqt-mt.so.3
#36 0xb68bc7c8 in QSignal::activate () from /usr/lib/libqt-mt.so.3
#37 0xb68c42b8 in QSingleShotTimer::event () from /usr/lib/libqt-mt.so.3
#38 0xb6834f3e in QApplication::internalNotify () from /usr/lib/libqt-mt.so.3
#39 0xb683513a in QApplication::notify () from /usr/lib/libqt-mt.so.3
#40 0xb6fcd1cd in KApplication::notify () from /usr/lib/libkdecore.so.4
#41 0xb67c6157 in QApplication::sendEvent () from /usr/lib/libqt-mt.so.3
#42 0xb682692b in QEventLoop::activateTimers () from /usr/lib/libqt-mt.so.3
#43 0xb67d9f67 in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#44 0xb684da2f in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#45 0xb684d952 in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#46 0xb6833a4d in QApplication::exec () from /usr/lib/libqt-mt.so.3
#47 0x0806dde8 in ?? ()
#48 0xbfb4cd70 in ?? ()
#49 0xbfb4cea4 in ?? ()
#50 0xbfb4ce9c in ?? ()
#51 0x00000000 in ?? ()

Best wishes, good work!
Marcin