There is a known problem with users connected only through BIS-B. I'm currently working on a fix (anyone with useful information is welcome to contact me ).
I have just posted a new version which might help with your issue. You can get more information on our blog (metromobile.blogspot.com) or on our web page (metro.nanika.net/index.php?p=MetroBB).
I'm sorry, I don't have the rights to post links here (too young ).