this is what I did to make xml errors fixing less mainful: 

1. run Lokalize (better with proper project opened)
2. ensure python and python-dbus is installed
3. run the following commands in konsole:

KDESVN=/home/xx/hacking/kde/trunk/
KDESVNLANG=ru

svn up $KDESVN/l10n-support/pology/
cd $KDESVN/l10n-kde4/$KDESVNLANG
$KDESVN/l10n-support/pology/scripts/posieve.py check-xml-kde4 -s lokalize messages

of course you should adjust vars to your situation, and instead of running the check
against whole messages/, you may want to specify e.g. messages/kdepim/