nepomukserver crashed with SIGSEGV in _int_free()

crashed after restart

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: kde-runtime 4:4.8.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-18.28-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.94-0ubuntu2
Architecture: amd64
Date: Tue Mar 6 19:45:39 2012
ExecutablePath: /usr/bin/nepomukserver
ProcCmdline: /usr/bin/nepomukserver
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f5ca0a38bd3 <_ZN9QHashData14detach_helper2EPFvPNS_4NodeEPvEPFvS1_Eii+227>: mov (%rax,%rdx,8),%rbx
 PC (0x7f5ca0a38bd3) ok
 source "(%rax,%rdx,8)" (0x00000071) not located in a known VMA region (needed readable region)!
 destination "%rbx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: kde-runtime
StacktraceTop:
 _int_free (av=0x7f5ca1fde720, p=0xcd7400, have_lock=0) at malloc.c:3961
 QMapData::continueFreeData(int) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
 ?? () from /usr/lib/libkdecore.so.5
 KConfig::~KConfig() () from /usr/lib/libkdecore.so.5
 KSharedConfig::~KSharedConfig() () from /usr/lib/libkdecore.so.5
Title: nepomukserver crashed with SIGSEGV in _int_free()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo vboxusers