Hi,

what were you doing when Okular crashed? Can you reproduce it? Does it happen with any document?
Also, the backtrace you provided is not useful. You can get a better one by following the instructions in:
http://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports

Thanks!

here's something that happens when run through GDB. Please tell me if this is enough.

Reproducibility: certain pdfs when viewed in "Slideshow" mode - dont go to slideshow at all. I mean a smaller window pops up. To close, I move my mouse to the top right corner and click and then the crash occurs.
Please note that the pdf was created from openoffice impress 3.0

[New Thread 0xb2d51b90 (LWP 7012)]                                            
[Thread 0xb2550b90 (LWP 7011) exited]                                         
Error: Couldn't create a font for 'BAAAAA+LiberationSerif-Regular'            
Error: Couldn't create a font for 'BAAAAA+LiberationSerif-Regular'            
[Thread 0xb2d51b90 (LWP 7012) exited]                                         
ASSERT failure in QVector<T>::operator[]: "index out of range", file /usr/include/qt4/QtCore/qvector.h, line 325

Program received signal SIGABRT, Aborted.
[Switching to Thread 0xb61548d0 (LWP 6935)]
0xb8042430 in __kernel_vsyscall ()
(gdb) bt
#0  0xb8042430 in __kernel_vsyscall ()
#1  0xb6812880 in raise () from /lib/tls/i686/cmov/libc.so.6
#2  0xb6814248 in abort () from /lib/tls/i686/cmov/libc.so.6
#3  0xb73ba795 in qt_message_output () from /usr/lib/libQtCore.so.4
#4  0xb73ba872 in qFatal () from /usr/lib/libQtCore.so.4
#5  0xb73ba8cc in qt_assert_x () from /usr/lib/libQtCore.so.4
#6  0xb4b9aa89 in ?? () from /usr/lib/kde4/okularpart.so
#7  0xb4b9b908 in ?? () from /usr/lib/kde4/okularpart.so
#8  0xb6bfa7cb in QWidget::event () from /usr/lib/libQtGui.so.4
#9  0xb4b950c3 in ?? () from /usr/lib/kde4/okularpart.so
#10 0xb6ba28ec in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#11 0xb6bab0e1 in QApplication::notify () from /usr/lib/libQtGui.so.4
#12 0xb7a5406d in KApplication::notify () from /usr/lib/libkdeui.so.5
#13 0xb74b2e61 in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#14 0xb6baa36e in QApplicationPrivate::sendMouseEvent () from /usr/lib/libQtGui.so.4
#15 0xb6c14656 in ?? () from /usr/lib/libQtGui.so.4
#16 0xb6c139e5 in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#17 0xb6c3d7aa in ?? () from /usr/lib/libQtGui.so.4
#18 0xb648a6f8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#19 0xb648dda3 in ?? () from /usr/lib/libglib-2.0.so.0
#20 0xb648df61 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#21 0xb74dd478 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#22 0xb6c3cea5 in ?? () from /usr/lib/libQtGui.so.4
#23 0xb74b152a in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#24 0xb74b16ea in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#25 0xb74b3da5 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#26 0xb6ba2767 in QApplication::exec () from /usr/lib/libQtGui.so.4
#27 0x0804e497 in _start ()
(gdb)

This is the same output as outputted with the crash dialog.
You need to install the packages of your distro that provide debug symbols for Okular (part of kdegraphics).

This looks like another case of the problem reported in bug #180291.

Please test again once KDE 4.2.2 is out; if you can reproduce, please reopen this bug.

*** This bug has been marked as a duplicate of bug 180291 ***