Did you just install a firewall? What about using a proxy? What settings are different that you are able to log in from other computer systems? Do you have a "Block Referred" enabled somewhere? Any on of these things could potentially lead to a denied access on any Xoops system.
The problem posted on Xoops has nothing to do with this situation. The "mainfile" is up to date and has been for almost two years. It has to be something to do with your internet settings/browser settings. Also, this doesn't sound like an ISP problem. If the problem continues after you've tweaked your settings, let us know.
:pint:
