Marketpress translation with .po - Page content not translated

I am using the .po and .mo files to offer my store in two languages (English as main and German as second). I have translated the bits I need from the .po file and most text elements are correctly translated and displayed. However the text on the store pages (on the Products -> Store Settings -> Messages tab) is not being translated. The translation exists in the .po/.mo files, but doesn't show. Any ideas for what is going wrong here?

I am using:
Wordpress 3.3.1
WPML Multilingual CMS 2.4.2
WPML Marketpress 1.1.1
Marketpress 2.4.2

An example of the problem is the English text showing up in http://www.swiss-wine-online.com/de/shop/order-status