Application that crashed: kcmshell4
Version of the application: 
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.5.3
Operating System: Linux 2.6.32-trunk-amd64 x86_64
Distribution: Debian GNU/Linux testing (squeeze)

What I was doing when the application crashed:
Steps to reproduce: 

Open K3b
Go to Settings menu
Select 'Setup System Premissions' option

K3b immediately crashes.

 -- Backtrace:
Application: KDE Control Module (kcmshell4), signal: Aborted
The current source language is "auto; currently c".
[KCrash Handler]
#5  0x00007f1dda288f55 in *__GI_raise (sig=<value optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#6  0x00007f1dda28bd90 in *__GI_abort () at abort.c:88
#7  0x00007f1dda2be58d in __libc_message (do_abort=2, 
    fmt=0x7fffac924070 "ff601000 r-xp 00000000 00:00 0", ' ' <repeats 18 times>, "[vsyscall]\n0000000 00:00 0 \n7f1dda9bb000-7f1dda9c1000 r--s 00000000 08:11 1032393", ' ' <repeats 20 times>, "/var/cache/fontconfig/105b9c7e6f0a4f82d8c9b6e39c52c"...) at ../sysdeps/unix/sysv/linux/libc_fatal.c:173
#8  0x00007f1dda2c7d56 in malloc_printerr (action=3, str=0x7f1dda372850 "double free or corruption (fasttop)", ptr=<value optimized out>) at malloc.c:6239
#9  0x00007f1dda2cc9bc in *__GI___libc_free (mem=<value optimized out>) at malloc.c:3738
#10 0x00007f1dcc0998d6 in PolkitQt::Context::Private::init() () from /usr/lib/libpolkit-qt-core.so.0
#11 0x00007f1dcc09b2cd in PolkitQt::Context::hasError() const () from /usr/lib/libpolkit-qt-core.so.0
#12 0x00007f1dcc095615 in PolkitQt::Auth::isCallerAuthorized(_PolKitAction*, long long, bool) () from /usr/lib/libpolkit-qt-core.so.0
#13 0x00007f1dcbe89a98 in PolkitQt::Action::Private::computePkResult() () from /usr/lib/libpolkit-qt-gui.so.0
#14 0x00007f1dcbe8a931 in PolkitQt::Action::setPolkitAction(QString const&) () from /usr/lib/libpolkit-qt-gui.so.0
#15 0x00007f1dcbe8aa17 in PolkitQt::Action::Action(QString const&, QObject*) () from /usr/lib/libpolkit-qt-gui.so.0
#16 0x00007f1dcc2aa129 in K3bSetup (this=0x2173aa0, parent=0x2239b10) at /tmp/buildd/k3b-1.70.0~beta1/k3bsetup/k3bsetup.cpp:78
#17 0x00007f1dcc2aca95 in KPluginFactory::createInstance<K3bSetup, QWidget> (parentWidget=<value optimized out>, parent=<value optimized out>, args=...) at /usr/include/kpluginfactory.h:461
#18 0x00007f1dd97570fe in KPluginFactory::create (this=0x21f76a0, iface=0x7f1dd9d76f60 "KCModule", parentWidget=<value optimized out>, parent=0x2239b10, args=..., keyword=<value optimized out>)
    at ../../kdecore/util/kpluginfactory.cpp:191
#19 0x00007f1dda022e66 in KPluginFactory::create<KCModule> (mod=..., report=KCModuleLoader::Inline, parent=0x2239b10, args=...) at ../../kdecore/util/kpluginfactory.h:515
#20 KService::createInstance<KCModule> (mod=..., report=KCModuleLoader::Inline, parent=0x2239b10, args=...) at ../../kdecore/services/kservice.h:517
#21 KService::createInstance<KCModule> (mod=..., report=KCModuleLoader::Inline, parent=0x2239b10, args=...) at ../../kdecore/services/kservice.h:494
#22 KService::createInstance<KCModule> (mod=..., report=KCModuleLoader::Inline, parent=0x2239b10, args=...) at ../../kdecore/services/kservice.h:534
#23 KCModuleLoader::loadModule (mod=..., report=KCModuleLoader::Inline, parent=0x2239b10, args=...) at ../../kutils/kcmoduleloader.cpp:89
#24 0x00007f1dda028597 in KCModuleProxyPrivate::loadModule (this=0x2236050) at ../../kutils/kcmoduleproxy.cpp:104
#25 0x00007f1dda029605 in KCModuleProxy::realModule (this=<value optimized out>) at ../../kutils/kcmoduleproxy.cpp:81
#26 0x00007f1dda02972c in KCModuleProxy::buttons (this=0x185e) at ../../kutils/kcmoduleproxy.cpp:297
#27 0x00007f1dda024017 in KCMultiDialogPrivate::updateButtons (this=<value optimized out>, currentModule=0x185e) at ../../kutils/kcmultidialog.cpp:71
#28 0x00007f1dda0255dc in KCMultiDialog::addModule (this=0x21f0be0, moduleInfo=<value optimized out>, parentItem=<value optimized out>, args=<value optimized out>)
    at ../../kutils/kcmultidialog.cpp:342
#29 0x00007f1dda5b2cd6 in kdemain (_argc=<value optimized out>, _argv=<value optimized out>) at ../../kcmshell/main.cpp:260
#30 0x00007f1dda275abd in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, 
    rtld_fini=<value optimized out>, stack_end=0x7fffac926678) at libc-start.c:222
#31 0x0000000000400649 in _start ()

Reported using DrKonqi