Please can you paste a backtrace of the crash in this bug report.

Ah indeed, forgot yesterday. Here it is : 

Application: Telepathy Integration Daemon (telepathy-integration-daemon), signal: Segmentation fault
[KCrash Handler]
#7  QMutex::lock (this=0x81b54cc) at thread/qmutex.cpp:150
#8  0xb59d03c3 in relock (this=0x824b7a0, __in_chrg=<value optimized out>) at /usr/include/QtCore/qmutex.h:120
#9  QMutexLocker (this=0x824b7a0, __in_chrg=<value optimized out>) at /usr/include/QtCore/qmutex.h:102
#10 Soprano::Client::SocketHandler::~SocketHandler (this=0x824b7a0, __in_chrg=<value optimized out>) at /usr/src/debug/soprano-2.5.0/client/clientconnection.cpp:58
#11 0xb59d0452 in Soprano::Client::SocketHandler::~SocketHandler (this=0x824b7a0, __in_chrg=<value optimized out>) at /usr/src/debug/soprano-2.5.0/client/clientconnection.cpp:61
#12 0xb59d2ff3 in QThreadStorage<Soprano::Client::SocketHandler*>::deleteData (x=0x824b7a0) at /usr/include/QtCore/qthreadstorage.h:133
#13 0xb7077180 in QThreadStorageData::set (this=0x8419200, p=0x83b0778) at thread/qthreadstorage.cpp:148
#14 0xb59d05fa in qThreadStorage_setLocalData<Soprano::Client::SocketHandler> (this=0x8472140) at /usr/include/QtCore/qthreadstorage.h:92
#15 setLocalData (this=0x8472140) at /usr/include/QtCore/qthreadstorage.h:148
#16 Soprano::Client::ClientConnection::socketForCurrentThread (this=0x8472140) at /usr/src/debug/soprano-2.5.0/client/clientconnection.cpp:95
#17 0xb59d2bbf in Soprano::Client::ClientConnection::connectInCurrentThread (this=0x8472140) at /usr/src/debug/soprano-2.5.0/client/clientconnection.cpp:754
#18 0xb59cf9d3 in Soprano::Client::LocalSocketClient::connect (this=0x81b8564, name=...) at /usr/src/debug/soprano-2.5.0/client/localsocketclient.cpp:141
#19 0xb6f8fee0 in init (this=0x81b44a8) at /usr/src/debug/kdelibs-4.5.1/nepomuk/core/nepomukmainmodel.cpp:102
#20 Nepomuk::MainModel::init (this=0x81b44a8) at /usr/src/debug/kdelibs-4.5.1/nepomuk/core/nepomukmainmodel.cpp:176
#21 0xb6f90916 in Nepomuk::ResourceManager::init (this=0x81b4840) at /usr/src/debug/kdelibs-4.5.1/nepomuk/core/resourcemanager.cpp:329
#22 0xb6fae0cb in Nepomuk::ResourceManagerPrivate::_k_storageServiceInitialized (this=0x80fd400, success=true) at /usr/src/debug/kdelibs-4.5.1/nepomuk/core/resourcemanager.cpp:220
#23 0xb6fae1f1 in Nepomuk::ResourceManager::qt_metacall (this=0x81b4840, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0xbfa0357c)
    at /usr/src/debug/kdelibs-4.5.1/build/nepomuk/resourcemanager.moc:90
#24 0xb757ca37 in QDBusConnectionPrivate::deliverCall (this=0x80f2648, object=0x81b4840, msg=..., metaTypes=..., slotIdx=136008908) at qdbusintegrator.cpp:904
#25 0xb758a536 in QDBusCallDeliveryEvent::placeMetaCall (this=0x84118c8, object=0x81b4840) at qdbusintegrator_p.h:101
#26 0xb718593f in QObject::event (this=0x81b4840, e=0x84118c8) at kernel/qobject.cpp:1248
#27 0xb6232c64 in QApplicationPrivate::notify_helper (this=0x80fb390, receiver=0x81b4840, e=0x84118c8) at kernel/qapplication.cpp:4302
#28 0xb623abf7 in QApplication::notify (this=0xbfa03de8, receiver=0x81b4840, e=0x84118c8) at kernel/qapplication.cpp:3706
#29 0xb5e3b361 in KApplication::notify (this=0xbfa03de8, receiver=0x81b4840, event=0x84118c8) at /usr/src/debug/kdelibs-4.5.1/kdeui/kernel/kapplication.cpp:310
#30 0xb7172e0e in QCoreApplication::notifyInternal (this=0xbfa03de8, receiver=0x81b4840, event=0x84118c8) at kernel/qcoreapplication.cpp:726
#31 0xb71769b4 in sendEvent (receiver=0x0, event_type=0, data=0x80d5f68) at kernel/qcoreapplication.h:215
#32 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x80d5f68) at kernel/qcoreapplication.cpp:1367
#33 0xb7176b9c in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1260
#34 0xb719e83d in sendPostedEvents (s=0x80fd510) at kernel/qcoreapplication.h:220
#35 postEventSourceDispatch (s=0x80fd510) at kernel/qeventdispatcher_glib.cpp:276
#36 0xb5a52b49 in g_main_dispatch (context=0x80fd490) at gmain.c:1960
#37 IA__g_main_context_dispatch (context=0x80fd490) at gmain.c:2513
#38 0xb5a53350 in g_main_context_iterate (context=0x80fd490, block=1, dispatch=1, self=0x80f83a8) at gmain.c:2591
#39 0xb5a5360e in IA__g_main_context_iteration (context=0x80fd490, may_block=1) at gmain.c:2654
#40 0xb719ed4b in QEventDispatcherGlib::processEvents (this=0x80da1f0, flags=...) at kernel/qeventdispatcher_glib.cpp:412
#41 0xb62e319a in QGuiEventDispatcherGlib::processEvents (this=0x80da1f0, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#42 0xb717211d in QEventLoop::processEvents (this=0xbfa03d44, flags=...) at kernel/qeventloop.cpp:149
#43 0xb7172319 in QEventLoop::exec (this=0xbfa03d44, flags=...) at kernel/qeventloop.cpp:201
#44 0xb7176c70 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1003
#45 0xb6230164 in QApplication::exec () at kernel/qapplication.cpp:3581
#46 0x0804e176 in main (argc=) at /home/gaboo/progs/telepathy/telepathy-integration-daemon/main.cpp:85

The telepathy-integration-daemon is now a Nepomuk service. It should now behave properly if Nepomuk is restarted.