Edit the Dutch version of Cushy CMS. It's not really Dutch now...
Please contact firstname.lastname@example.org if you are interested in providing changes to existing translations.
I really appreciate the effort to offer Cushy in more languages, but the Dutch translation is currently so bad that I'm almost ashamed to offer this to clients.
I don't know if you hired someone to do the translation or used software to do it automatically, but in the first case you should ask your money back and in the second case you should just drop it.