Not sure if this will help or not as I've seen similar issues, but not the exact ones you describe. If you could answer the following it might help.
Is your MBG and MAS co-located or do you have a separate MBG?
Is your MBG/MAS sitting directly on the outside, or is it behind a firewall? If behind a firewall, what ports are forwarded to the MBG? Specifically is SSH forwarded?
If its sitting directly on the outside, do you have it available to any/all networks for Admin access? (Specifically what networks, if any, are listed in the Remote Management section of the Remote Access area under Security on either the MAS or MBG.)