I'm not sure which comments you're referring to. Could you give us a link to an album, and tell us exactly where you're seeing English instead of Deutsch?
That's the jAlbum widget bar. I believe the underlying script tries to figure out, from your IP address, where you're located, then chooses the correct language. Perhaps Anders can shed some light on this.
I'll move this thread to the "widgets" forum section.
It actually checks the language that is set in your web browser and tries to use that language.
However, if you have visited jalbum.net it uses the language you used there. So if you want to switch language you have to go to jalbum.net and switch language. There is also a cache time, so even if you switch language the widgets are not immediately updated, unless you also empty the browsers cache.