Problem after upgrading to SC 4.6

[gavdari]

I have updated to KDE4.6 and on the first boot, I am stopped by the following error:

Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0xb618c940 (LWP 1463))]

Thread 4 (Thread 0xae1ffb70 (LWP 1466)):
#0 0x00c6a15f in ?? () from /lib/libc.so.6
#1 0x00c4de08 in poll () from /lib/libc.so.6
#2 0x0328da1b in g_poll () from /lib/libglib-2.0.so.0
#3 0x0328043c in ?? () from /lib/libglib-2.0.so.0
#4 0x03280848 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#5 0x022bc59f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#6 0x0228c609 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#7 0x0228ca8a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#8 0x02188b7e in QThread::exec() () from /usr/lib/libQtCore.so.4
#9 0x0226b35b in ?? () from /usr/lib/libQtCore.so.4
#10 0x0218bdf9 in ?? () from /usr/lib/libQtCore.so.4
#11 0x02cc9ba8 in ?? () from /usr/lib/nvidia-current/libGL.so.1

Thread 3 (Thread 0xacab8b70 (LWP 1467)):
#0 0x08020e36 in clock_gettime () from /lib/librt.so.1
#1 0x021e750b in ?? () from /usr/lib/libQtCore.so.4
#2 0x022be6e5 in ?? () from /usr/lib/libQtCore.so.4
#3 0x022be72a in ?? () from /usr/lib/libQtCore.so.4
#4 0x022bc7a8 in ?? () from /usr/lib/libQtCore.so.4
#5 0x022bc83d in ?? () from /usr/lib/libQtCore.so.4
#6 0x0327fe6a in g_main_context_prepare () from /lib/libglib-2.0.so.0
#7 0x03280279 in ?? () from /lib/libglib-2.0.so.0
#8 0x03280848 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#9 0x022bc59f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#10 0x0228c609 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#11 0x0228ca8a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#12 0x02188b7e in QThread::exec() () from /usr/lib/libQtCore.so.4
#13 0x0226b35b in ?? () from /usr/lib/libQtCore.so.4
#14 0x0218bdf9 in ?? () from /usr/lib/libQtCore.so.4
#15 0x02cc9ba8 in ?? () from /usr/lib/nvidia-current/libGL.so.1

Thread 2 (Thread 0xac2b7b70 (LWP 1468)):
#0 0x00289416 in __kernel_vsyscall ()
#1 0x02791884 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2 0x00c69df4 in pthread_cond_timedwait () from /lib/libc.so.6
#3 0x0218c94f in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#4 0x021805b3 in ?? () from /usr/lib/libQtCore.so.4
#5 0x0218bdf9 in ?? () from /usr/lib/libQtCore.so.4
#6 0x02cc9ba8 in ?? () from /usr/lib/nvidia-current/libGL.so.1

Thread 1 (Thread 0xb618c940 (LWP 1463)):
[KCrash Handler]
#7 0x01a0eed7 in QGraphicsItemPrivate::setVisibleHelper(bool, bool, bool) () from /usr/lib/libQtGui.so.4
#8 0x01a0f308 in QGraphicsItem::setVisible(bool) () from /usr/lib/libQtGui.so.4
#9 0x0391abf1 in ?? () from /usr/lib/kde4/plasma_applet_microblog.so
#10 0x0391d2ec in ?? () from /usr/lib/kde4/plasma_applet_microblog.so
#11 0x039179ab in ?? () from /usr/lib/kde4/plasma_applet_microblog.so
#12 0x004d6d3c in ?? () from /usr/lib/libplasma.so.3
#13 0x004ecfff in ?? () from /usr/lib/libplasma.so.3
#14 0x004edbec in Plasma::Corona::loadLayout(QString const&) () from /usr/lib/libplasma.so.3
#15 0x004ee7ee in Plasma::Corona::initializeLayout(QString const&) () from /usr/lib/libplasma.so.3
#16 0x00aec52a in ?? () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#17 0x00aec90b in ?? () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#18 0x00aef677 in ?? () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#19 0x022938ca in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/libQtCore.so.4
#20 0x0229edf6 in QMetaCallEvent::placeMetaCall(QObject*) () from /usr/lib/libQtCore.so.4
#21 0x022a06a2 in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#22 0x0228d9db in QCoreApplication::event(QEvent*) () from /usr/lib/libQtCore.so.4
#23 0x0136b4d4 in QApplication::event(QEvent*) () from /usr/lib/libQtGui.so.4
#24 0x01367fdc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#25 0x0136e04e in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#26 0x0104d82a in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#27 0x0228db3b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#28 0x02290d8b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQtCore.so.4
#29 0x02290f4d in QCoreApplication::sendPostedEvents(QObject*, int) () from /usr/lib/libQtCore.so.4
#30 0x022bca74 in ?? () from /usr/lib/libQtCore.so.4
#31 0x0327c855 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#32 0x03280668 in ?? () from /lib/libglib-2.0.so.0
#33 0x03280848 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#34 0x022bc565 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#35 0x01429be5 in ?? () from /usr/lib/libQtGui.so.4
#36 0x0228c609 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#37 0x0228ca8a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#38 0x0229100f in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#39 0x01366e07 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#40 0x00ace1e7 in kdemain () from /usr/lib/kde4/libkdeinit/libkdeinit4_plasma-desktop.so
#41 0x080485bb in _start ()

What should I do? I thought KDE 4.6 is the current final release. I don't know what caused the error.