The live example looks fine to you, or the code in a newer version than bbPress 2.0-beta-3 looks fine to you?
The live example clearly says:
“Dette forumet inneholder 0 topics og 0 replies.”
“topics” and “replies” are English words and should be translatable. They aren’t.
This one is not resolved properly with regards to localization.
In bbpress.pot, the original strings are:
This forum contains %1$s and %2$s.
This category contains %1$s and %2$s.
Even translated, these phrases have hard-coded English words for topics and replies.
topics and replies for these phrases are, in other words, not present in the bbpress.pot file, and cannot be translated.
