Application that crashed: kbluetooth4
Version of the application: 0.3
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.3
Operating System: Linux 2.6.31.6 x86_64
Distribution: "Fedora release 11 (Leonidas)"

What I was doing when the application crashed:
Using the RFkill button to disable Wifi also disables the bluetooth device, and this causes kbluetooth4 to crash. Apparently the same crash as reported here by many other people. Mostly this is annoying because the rfwill button is touch-sensitive on my HP HDX18 laptop, and I frequently trigger the kbluetooth4 crash inadvertently.

 -- Backtrace:
Application: KBluetooth4 - The KDE4 Bluetooth Framework (kbluetooth4), signal: Segmentation fault
[KCrash Handler]
#5  0x00007f09322b3330 in QObject::property (this=0xa4fc50, name=0x7f09325eb6e0 "_qdbus_slotCache") at kernel/qobject.cpp:3292
#6  0x00007f09325b7c8e in QDBusConnectionPrivate::activateCall (this=<value optimized out>, object=0xa4fc50, flags=273, msg=@0xa3fbc0) at qdbusintegrator.cpp:753
#7  0x00007f09325b8887 in QDBusConnectionPrivate::activateObject (this=<value optimized out>, node=@0xa3fb98, msg=<value optimized out>, pathStartPos=<value optimized out>)
    at qdbusintegrator.cpp:1347
#8  0x00007f09325b8af8 in QDBusActivateObjectEvent::placeMetaCall (this=0xa3fb50) at qdbusintegrator.cpp:1464
#9  0x00007f09322b1141 in QObject::event (this=0x7fff57b4d4d0, e=0xa3fb50) at kernel/qobject.cpp:1110
#10 0x00007f093154420d in QApplication::event (this=0x7fff57b4d4d0, e=0xa3fb50) at kernel/qapplication.cpp:2317
#11 0x00007f093153a63c in QApplicationPrivate::notify_helper (this=0x88b390, receiver=0x7fff57b4d4d0, e=0xa3fb50) at kernel/qapplication.cpp:4065
#12 0x00007f093154189e in QApplication::notify (this=0x7fff57b4d4d0, receiver=0x7fff57b4d4d0, e=0xa3fb50) at kernel/qapplication.cpp:4030
#13 0x00007f0933da17f6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib64/libkdeui.so.5
#14 0x00007f09322a1bac in QCoreApplication::notifyInternal (this=0x7fff57b4d4d0, receiver=0x7fff57b4d4d0, event=0xa3fb50) at kernel/qcoreapplication.cpp:610
#15 0x00007f09322a2782 in QCoreApplication::sendEvent (event=<value optimized out>, receiver=<value optimized out>) at kernel/qcoreapplication.h:213
#16 QCoreApplicationPrivate::sendPostedEvents (event=<value optimized out>, receiver=<value optimized out>) at kernel/qcoreapplication.cpp:1247
#17 0x00007f09322ca2c3 in QCoreApplication::sendPostedEvents () at kernel/qcoreapplication.h:218
#18 postEventSourceDispatch () at kernel/qeventdispatcher_glib.cpp:210
#19 0x00007f092d16f90e in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#20 0x00007f092d1730e8 in ?? () from /lib64/libglib-2.0.so.0
#21 0x00007f092d17320a in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#22 0x00007f09322c9f36 in QEventDispatcherGlib::processEvents (this=0x860b10, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#23 0x00007f09315cd02e in QGuiEventDispatcherGlib::processEvents (this=0xa4fc50, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#24 0x00007f09322a04b2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 37}) at kernel/qeventloop.cpp:149
#25 0x00007f09322a0884 in QEventLoop::exec (this=0x7fff57b4bd60, flags={i = 5}) at kernel/qeventloop.cpp:201
#26 0x00007f09325bbce5 in QDBusConnectionPrivate::sendWithReply (this=0xa60630, message=<value optimized out>, sendMode=<value optimized out>, timeout=<value optimized out>)
    at qdbusintegrator.cpp:1782
#27 0x00007f09325a7943 in QDBusConnection::call (this=0x9cf6c0, message=@0x7f09325eb6e0, mode=10746816, timeout=8969512) at qdbusconnection.cpp:516
#28 0x00007f09325c1c5c in QDBusAbstractInterface::callWithArgumentList (this=<value optimized out>, mode=QDBus::BlockWithGui, method=<value optimized out>, args=<value optimized out>)
    at qdbusabstractinterface.cpp:402
#29 0x00007f09325c52a3 in QDBusAbstractInterface::call (this=<value optimized out>, mode=<value optimized out>, method=<value optimized out>, arg1=<value optimized out>, arg2=@0xbf7, 
    arg3=@0x7fff57b4c2e0, arg4=@0x7fff57b4c2d0, arg5=@0x7fff57b4c2c0, arg6=@0x7fff57b4c2b0, arg7=@0x7fff57b4c2a0, arg8=@0x7fff57b4c290) at qdbusabstractinterface.cpp:655
#30 0x0000000000420d5e in _start ()

Reported using DrKonqi