Version:           Version 4.1.2 (KDE 4.1.2) (KDEmod) (using KDE 4.1.2)
Compiler:          gcc 
OS:                Linux
Installed from:    Unlisted Binary Package

Using:
Qt: 4.4.3
KDE: 4.1.2 (KDE 4.1.2)
JuK: 3.1.1

( I use es_AR locale (kde-l10n-es) , but trying to reproduce this bug with LANG=en I got another backtrace with an assert (strange) )

Steps to reproduce:

- Open JUK
- Go to Settings / Configure Shortcuts 
- Select the global shortcut of "Next", the keyboard shortcut configuration widget appears in the row.
- Without closing it or selecting any key, select "None" in "Global shortcut" groupbox below
- The keyboard shortcut configuration widget will be closed and the whole list updated (with no key shortcuts)
- Select the global shortcut of "Next" again . Crash

(May be the shortcut can be other than "Next", and the Global Shortcut Option can be another than "None". I've encountered this crash with other combination of these two options)

I don't know where to post this bug because the backtrace is kdelibs related ( shortcuteditor ), but Juk is which triggers the crash because of its "Global Shortcut Option" to set the whole keyboard shortcuts scheme

Backtrace (when using LANG=en) 

 Aplicación: JuK (juk), señal SIGABRT
[Thread debugging using libthread_db enabled]
[New Thread 0xb56be700 (LWP 16867)]
[New Thread 0xb1152b90 (LWP 16874)]
[New Thread 0xb1953b90 (LWP 16873)]
[New Thread 0xb2154b90 (LWP 16872)]
[New Thread 0xb2955b90 (LWP 16871)]
[New Thread 0xb319fb90 (LWP 16868)]
[KCrash handler]
#6  0xb804a424 in __kernel_vsyscall ()
#7  0xb5ccb720 in raise () from /lib/libc.so.6
#8  0xb5ccd058 in abort () from /lib/libc.so.6
#9  0xb7ec6965 in qt_message_output () from /usr/lib/libQtCore.so.4
#10 0xb7ec6a17 in qFatal () from /usr/lib/libQtCore.so.4
#11 0xb7ec6aa6 in qt_assert () from /usr/lib/libQtCore.so.4
#12 0xb7a1f995 in KShortcutsEditorDelegate::itemActivated (this=0x8d2b4e0, 
    index={r = -1077524656, c = 16, p = 0xbfc6483c, m = 0xb6632f60})
    at /home/jan/Dev/packages/kdemod-core/work/kdelibs/src/kdelibs-4.1.2/kdeui/dialogs/kshortcutseditordelegate.cpp:119
#13 0xb7a27704 in KShortcutsEditorDelegate::qt_metacall (this=0x8d2b4e0, 
    _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfc6483c)
    at /home/jan/Dev/packages/kdemod-core/work/kdelibs/src/build/kdeui/kshortcutsdialog_p.moc:82
#14 0xb7fbbb03 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#15 0xb7fbc063 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#16 0xb64505a4 in QAbstractItemView::clicked () from /usr/lib/libQtGui.so.4
#17 0xb645d5c4 in QAbstractItemView::mouseReleaseEvent ()
   from /usr/lib/libQtGui.so.4
#18 0xb6492ad4 in QTreeView::mouseReleaseEvent () from /usr/lib/libQtGui.so.4
#19 0xb604ec5e in QWidget::event () from /usr/lib/libQtGui.so.4
#20 0xb6338204 in QFrame::event () from /usr/lib/libQtGui.so.4
#21 0xb63c2f57 in QAbstractScrollArea::viewportEvent ()
   from /usr/lib/libQtGui.so.4
#22 0xb645de5f in QAbstractItemView::viewportEvent ()
   from /usr/lib/libQtGui.so.4
#23 0xb6492d39 in QTreeView::viewportEvent () from /usr/lib/libQtGui.so.4
#24 0xb63c5375 in ?? () from /usr/lib/libQtGui.so.4
#25 0x08cf0610 in ?? ()
#26 0xbfc651cc in ?? ()
#27 0xbfc64d08 in ?? ()
#28 0xb7fa9120 in QCoreApplicationPrivate::sendThroughObjectEventFilters ()
   from /usr/lib/libQtCore.so.4
Backtrace stopped: frame did not save the PC
#0  0xb804a424 in __kernel_vsyscall ()

ASSERT: "oldItem" in file /home/jan/Dev/packages/kdemod-core/work/kdelibs/src/kdelibs-4.1.2/kdeui/dialogs/kshortcutseditordelegate.cpp, line119

Another backtrace (when using es_AR):

Aplicación: JuK (juk), señal SIGSEGV
[Thread debugging using libthread_db enabled]
[New Thread 0xb5578700 (LWP 16894)]
[New Thread 0xb0f4cb90 (LWP 16901)]
[New Thread 0xb174db90 (LWP 16900)]
[New Thread 0xb1f4eb90 (LWP 16899)]
[New Thread 0xb274fb90 (LWP 16898)]
[New Thread 0xb2f99b90 (LWP 16895)]
[KCrash handler]
#6  0xb637a1b5 in ?? () from /usr/lib/libQtGui.so.4
#7  0xbf91eae8 in ?? ()
#8  0xb792f937 in KExtendableItemDelegate::isExtended (this=0xbf91eb34, 
    index=@0x995b8e0)
    at /home/jan/Dev/packages/kdemod-core/work/kdelibs/src/kdelibs-4.1.2/kdeui/itemviews/kextendableitemdelegate.cpp:165
#9  0xb637a3be in ?? () from /usr/lib/libQtGui.so.4
#10 0xbf91eb34 in ?? ()
#11 0x0995b8e0 in ?? ()
#12 0x6374726f in ?? ()
#13 0x00000000 in ?? ()
#0  0xb7f04424 in __kernel_vsyscall ()