BuddyPress.org

Jebus. That is one F’ed up function. It uses three different ways to get what should be the same data.

$home_root = parse_url(get_option('home'));

$base = trailingslashit( get_bloginfo( 'home' ) );

$base = trailingslashit( get_bloginfo( 'url' ) );

These *should* all return the same value and I can’t see anywhere else that the code would potentially break. The only thing I can suggest is to dump those three values above and make sure they all match.

The only other thing I see is to ensure that you aren’t using the default permalink structure. I think you have to change this to use BP though so that shouldn’t be your problem.