Version:           4.8 (using KDE 4.7.4) 
OS:                Linux

since my kubuntu update to KDE 4.8 kmail doesn't start up anymore.

Reproducible: Always

Steps to Reproduce:
try to start kmail

Actual Results:  
crash window after a second

Expected Results:  
kmail or kontact visible and functional ;-)

Here is the framestack:

Application: KMail (kmail), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f0c7f98f7a0 (LWP 7586))]

Thread 3 (Thread 0x7f0c5feaf700 (LWP 7590)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f0c71c2ec2c in ?? () from /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4
#2  0x00007f0c71c2ed59 in ?? () from /usr/lib/x86_64-linux-gnu/libQtWebKit.so.4
#3  0x00007f0c7a8abefc in start_thread (arg=0x7f0c5feaf700) at pthread_create.c:304
#4  0x00007f0c7cd0589d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f0c5f5ae700 (LWP 7591)):
#0  0x00007f0c7571ef16 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f0c7571f429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f0c7d677f3e in QEventDispatcherGlib::processEvents (this=0x27389c0, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#3  0x00007f0c7d64bcf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#4  0x00007f0c7d64bef7 in QEventLoop::exec (this=0x7f0c5f5adde0, flags=...) at kernel/qeventloop.cpp:201
#5  0x00007f0c7d56327f in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#6  0x00007f0c7d565d05 in QThreadPrivate::start (arg=0x2737ad0) at thread/qthread_unix.cpp:331
#7  0x00007f0c7a8abefc in start_thread (arg=0x7f0c5f5ae700) at pthread_create.c:304
#8  0x00007f0c7cd0589d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#9  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f0c7f98f7a0 (LWP 7586)):
[KCrash Handler]
#6  data (this=0x8) at ../../include/QtCore/../../src/corelib/tools/qscopedpointer.h:135
#7  qGetPtrHelper<QScopedPointer<QObjectData> > (p=...) at ../../include/QtCore/../../src/corelib/global/qglobal.h:2343
#8  d_func (this=0x0) at kernel/qaction.h:67
#9  QAction::setText (this=0x0, text=...) at kernel/qaction.cpp:814
#10 0x00007f0c7e78a6ca in KMMainWidget::updateFolderMenu() () from /usr/lib/libkmailprivate.so.4
#11 0x00007f0c7e793640 in KMMainWidget::setupActions() () from /usr/lib/libkmailprivate.so.4
#12 0x00007f0c7e79b1e8 in KMMainWidget::KMMainWidget(QWidget*, KXMLGUIClient*, KActionCollection*, KSharedPtr<KSharedConfig>) () from /usr/lib/libkmailprivate.so.4
#13 0x00007f0c7e6fadb5 in ?? () from /usr/lib/libkmailprivate.so.4
#14 0x00007f0c7e74eee7 in KMKernel::openReader(bool) () from /usr/lib/libkmailprivate.so.4
#15 0x00007f0c7e750228 in KMKernel::action(bool, bool, QString const&, QString const&, QString const&, QString const&, QString const&, KUrl const&, KUrl::List const&, QStringList const&) () from /usr/lib/libkmailprivate.so.4
#16 0x00007f0c7e75100f in KMKernel::handleCommandLine(bool) () from /usr/lib/libkmailprivate.so.4
#17 0x0000000000403237 in _start ()