Does not translate the Top-Navigation (slug)

Hi there,

im using the BP Social Theme and already installed german-Language for WPMU and BP. All works fine! Except: It does not translate the Top-Navigation (slugs). Among with some more, but most important now is Top-Navigation.

In navigation.php:
<?php _e( 'Members','bp-corp' ) ?>

In PO-File, downloaded from the needed lines are there
msgid "Members"
msgstr "Mitglieder"

My guess is, that the 'bp-corp' messes up the whole thing. Am I right with that? And what can I do, to make it work?