Version:            (using KDE KDE 3.0.3)
Installed from:    RedHat RPMs
OS:          Linux

I close some project files . i use the tab style and i close some open files with the x button in the upper right corner.
i wnated to leave only one file open and when i had only two files open left i tried to close the one i didnt want and then the program crushed
it happend only one time. i used to do it alot and it never accured again.
I hope this wull help you (this is the output i got after the program crushed): 

(no debugging symbols found)...[New Thread 8192 (LWP 975)]
0x420ae169 in wait4 () from /lib/i686/libc.so.6
#0  0x420ae169 in wait4 () from /lib/i686/libc.so.6
#1  0x4212a2d0 in __DTOR_END__ () from /lib/i686/libc.so.6
#2  0x41302c63 in waitpid () from /lib/i686/libpthread.so.0
#3  0x40a171a5 in KCrash::defaultCrashHandler(int) ()
   from /usr/lib/libkdecore.so.4
#4  <signal handler called>
#5  0x00000049 in ?? ()
#6  0x4014f08d in QextMdiMainFrm::qt_invoke(int, QUObject*) (this=0x830e2c8,
    _id=116, _o=0xbffff240) at qextmdimainfrm.moc:358
#7  0x081f6911 in CKDevelop::qt_invoke(int, QUObject*) ()
#8  0x40dc7d6b in QObject::activate_signal(QConnectionList*, QUObject*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#9  0x40dc7c57 in QObject::activate_signal(int) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#10 0x41094b4e in QButton::clicked() ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#11 0x40e49c76 in QButton::mouseReleaseEvent(QMouseEvent*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#12 0x40dfc36c in QWidget::event(QEvent*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#13 0x40d73c49 in QApplication::internalNotify(QObject*, QEvent*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#14 0x40d73363 in QApplication::notify(QObject*, QEvent*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#15 0x409ab9a6 in KApplication::notify(QObject*, QEvent*) ()
   from /usr/lib/libkdecore.so.4
#16 0x40d17b46 in QETWidget::translateMouseEvent(_XEvent const*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#17 0x40d149b6 in QApplication::x11ProcessEvent(_XEvent*) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#18 0x40d1452f in QApplication::processNextEvent(bool) ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#19 0x40d75280 in QApplication::enter_loop() ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#20 0x40d1402d in QApplication::exec() ()
   from /usr/lib/qt3-gcc3.2/lib/libqt-mt.so.3
#21 0x081235c2 in main ()
#22 0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6