The texts in there are only read by KDE apps. To fix qt's ts files I had to do the following

msgfmt to create a shadow dir
echo "<TS>" > tt.ts; grep i18n qt3.spec.cpp | sed -e 's,i18n(",,; s,");,,'| while read line; do context=`grep "$line\"" qt333 | sed -e 's,msgid ",,; s,::.*,,'`; echo $context:$line; trans=`gettext -d qt3 "$line"`; echo "<context><name>$context</name><message><source>$line</source><translation>$trans</translation></message></context>" | sed -e "s,&,&amp;,g" >> tt.ts;  done; echo "</TS>" >> tt.ts ; xmllint --format tt.ts >> qt_de.ts

After that I had to manually merged the XML trees and merge duplicated contexts. Pretty hairy actually ;(