Version:           4.0 (using KDE 3.97.1 (KDE 4.0 >= 20080101), compiled sources)
Compiler:          gcc
OS:                Linux (i686) release 2.6.22-3-686

Every time KNotify wants to tell me something, it crashes.
On KDE startup it crashed with a different crash manager windows than all the other times. Interesting is that this first crashmanager window itself crashes ...
Anyway, here's the backtrace, one of the crashmanagers gave me.
I hope it helps:

Using host libthread_db library "/lib/i686/cmov/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 0xb6a18920 (LWP 29607)]
[New Thread 0xb3e7bb90 (LWP 29611)]
[New Thread 0xb467cb90 (LWP 29610)]
[KCrash handler]
#6  0xffffe410 in __kernel_vsyscall ()
#7  0xb6caeeb5 in raise () from /lib/i686/cmov/libc.so.6
#8  0xb6cb0831 in abort () from /lib/i686/cmov/libc.so.6
#9  0xb7e15a35 in qt_message_output () from /usr/lib/libQtCore.so.4
#10 0xb7e15ae9 in qFatal () from /usr/lib/libQtCore.so.4
#11 0xb7e15c75 in qt_assert () from /usr/lib/libQtCore.so.4
#12 0xb4e1997c in Phonon::Xine::XineEngine::nullPort ()
    at /root/kde/src/KDE/base/runtime/phonon/xine/xineengine.cpp:254
#13 0xb4e2049e in Phonon::Xine::XineStream::createStream (this=0x81845f0)
    at /root/kde/src/KDE/base/runtime/phonon/xine/xinestream.cpp:372
#14 0xb4e23af9 in Phonon::Xine::XineStream::event (this=0x81845f0, 
    ev=0x818c630)
    at /root/kde/src/KDE/base/runtime/phonon/xine/xinestream.cpp:931
#15 0xb74cc21d in QApplicationPrivate::notify_helper ()
   from /usr/lib/libQtGui.so.4
#16 0xb74cfc77 in QApplication::notify () from /usr/lib/libQtGui.so.4
#17 0xb71dc919 in KApplication::notify (this=0xbfdf8bbc, receiver=0x81845f0, 
    event=0x818c630)
    at /root/kde/src/KDE/libs/kdeui/kernel/kapplication.cpp:314
#18 0xb7ed0ffb in QCoreApplication::notifyInternal ()
   from /usr/lib/libQtCore.so.4
#19 0xb7ed27be in QCoreApplicationPrivate::sendPostedEvents ()
   from /usr/lib/libQtCore.so.4
#20 0xb7ed2aad in QCoreApplication::sendPostedEvents ()
   from /usr/lib/libQtCore.so.4
#21 0xb7ef4cdb in ?? () from /usr/lib/libQtCore.so.4
#22 0x00000000 in ?? ()

Thread 1 (Thread 0xb6a18920 (LWP 29607)):
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7dccaa5 in pthread_cond_wait@@GLIBC_2.3.2 ()
   from /lib/i686/cmov/libpthread.so.0
#2  0xb7e1c455 in ?? () from /usr/lib/libQtCore.so.4
#3  0x0817339c in ?? ()
#4  0x08173384 in ?? ()
#5  0x0813b008 in ?? ()
#6  0xb7e1c477 in ?? () from /usr/lib/libQtCore.so.4
#7  0xbfdf7f34 in ?? ()
#8  0x08173384 in ?? ()
#9  0xfffffc18 in ?? ()
#10 0xb6ced20e in ?? () from /lib/i686/cmov/libc.so.6
#11 0x00000000 in ?? ()
#0  0xffffe410 in __kernel_vsyscall ()