This shop system is absolutely great :-)
I use CodeIniter a lot and I was building a shop system on it. I quit straight away. This system is exactly what I was building.
I just started playing around today and translating to dutch. The thing is that I can make a language default but it is not used as fallback. For example if I add a language and klik on it on the front-end. The products are not translated (ofcource) but instead the default language should be used as fallback language.
An other thing is that the back-end is translated but stays english. Howcome? Where to change the default back-end language. A suggestion is to make a defualt and different per back-end user. (Like TypoLight does for example)
Third, it would be nice to add a second language system. The current system and an extra system like google translate. Translating on the fly including productinfo.
Keep up the good work. In the near future I will make contributions for dutch ideal and other payment possibilities.