4
Tried to register on your site to check the situation out, but got this message:
You are now registered. However, we were unable to send the activation mail to your email account due to an internal error that had occurred on our server. We are sorry for the inconvenience, please send the webmaster an email notifying him/her of the situation.
I notice that your forum and your article sections aren't accessible through your main menu, only the top menu. I know you said that you tried to edit the xoops_group_permission table, but have you checked group permissions in your admin section under Users-->Groups ? Or are you using the Multimenu module to just display certain sections on your Main Menu? Because if you aren't using multimenu and/or it isn't a custom block or you haven't set the modules weight to zero, those modules' should be visible on your Main Menu to anonymous users.