In the HTTP log we noticed a number of „404 not found“ errors and fixed them.
Turns out that if you visit a link (you don’t have a session yet) to an english category
and the shop automatically switches you to German (because your web browser says that you prefer German to English),
it will look for the English category name on the German server.
We added a number of redirects to fix this for all cases we could find.
there can still be some left over and we will keep our eyes open.