This seems to be a rather harmless error that prompts as a notification at launch. Third boot from freshly installed Ubuntu 12.04 Beta in VirtualBox, already updated packages.
ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: kde-runtime 4:4.8.2-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-21.34-generic 3.2.13
Uname: Linux 3.2.0-21-generic x86_64
ApportVersion: 2.0-0ubuntu4
Architecture: amd64
Date: Wed Apr 4 03:41:27 2012
Disassembly: => 0x0: No se puede acceder a la memoria en la dirección 0x0
ExecutablePath: /usr/bin/nepomukservicestub
InstallationMedia: Kubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328)
ProcCmdline: /usr/bin/nepomukservicestub nepomukfilewatch
ProcEnviron:
LANGUAGE=es_MX:es
LANG=es_MX.UTF-8
SHELL=/bin/bash
SegvReason:
executing NULL VMA
reading NULL VMA
Signal: 11
SourcePackage: kde-runtime
Title: nepomukservicestub crashed with SIGSEGV in QObject::~QObject()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
