missing configuration menu options in admin panel, in dutch

Today i upgraded my zencart from 1.3.9c to 1.5.4.
Everything seems to be functioning ok, but when i wanted to desable the maintenance mode I discoverd that the entire dropdown menu for configuration was missing. The only existing submenu is : Configuration>logbook.
For instance: I can not find Configuration>maintenance.
All the other menu items like catalogue, modules etc seem to be complete.
Does someone know how to fix this?

annedien:

Today i upgraded my zencart from 1.3.9c to 1.5.4.
Everything seems to be functioning ok, but when i wanted to desable the maintenance mode I discoverd that the entire dropdown menu for configuration was missing. The only existing submenu is : Configuration>logbook.
For instance: I can not find Configuration>maintenance.
All the other menu items like catalogue, modules etc seem to be complete.
Does someone know how to fix this?

Did you also upgrade your Dutch language files?

no. Where can i find/download the dutch upgrade file?

see my signature

Great! this was the solution! everything is back and functioning.
Beeing very happy :D