Default language issue

I am finishing the configuration on a new client site (he is not adverse to paying for the "Essential" license, but I would like to finish my work as simply as possible before going to the live server for the payment sandbox testing). I was testing the checkout process but couldn't get past issue with Joomla! users not being able to add an address, so I read up and the recommendation was an update. I did the update and, bar a few files where I have hacked out the pagination (good thing I backed up my Joomla! files first for reference), everything looked good.

The site I am creating is dual language (English primary and German secondary) but the customer wanted the e-commerce section of his site (this is a confusing site, but you have to work with the client) in English. We had set everything up in the previous version in English and everything was good.

The upgrade done I immediately notice that Hikashop is reading the German language file. Now, the simplest answer to my query is to hack the German language file with the English content and everybody is happy.....at least, until I am asked to take Hikashop dual language (once proof of concept is shown to work and he wants to upgrade his licence).

The weird part is that my default language in Joomla! is English and that is working across the rest of the site.

J! 1.5.22 (will do the upgrade to 1.5.23 before porting to the live server)
XAMPP installation
Hikashop 1.5.3 from 1.4.? (8 or 9 I think)

I have queried mySQL through phpmyadmin and it can't find a language option in the hikashop tables, so what is the solution. Sorry I couldn't be more succinct on this one, but this is how this project is for me...

Thanks for your suggestion. I am about to check it out (sounds like it should work if you have programmed it to fallback). However I thought I would check out your theory about it defaulting to the active language. I have the site in English (through the English menu using M17n) and the language file being called is still the German file.

I'll let you know how I get on with your suggestion once I've tried it.

Sometimes you just have egg on your face. It was nothing to do with the translations. This was me forgetting that there is a "Empty cart message override" in the hikashop_cart options. Whoops! Oh well, if there are any other doofi out there it will save them the embarrassment.