Forum selections in MCP queue not working

-> 'Approve Details' for any topic/post
-> (dis-)approve topic/post
-> confirm
-> return link sends you back and sets the forum_id (var 'f') to the one of the post/topic you just (dis-)approved
-> only topics/posts from that forum should be displayed: instead there are no topics/posts at all (not even from that very forum)
-> switch back to "All forums"
-> topics/posts appear again