Unless I'm missing something, it seems that there are a few items on the "Related" tab that can't be localized: the tab title itself is fine, but the contents (number of items related and the "add" button) as well as parts of the dialog that allows you to select items to be related cannot be localized through BabelZilla.

Also, anybody who wants to test/help out with the German translation should let me know!

Edit: Also, the "Related: [click here]" and "Tags: [click here]" on Snapshots and Links cannot be localized.