Are you using the latest version of mojoPortal?
I would view the source of the rendered page and see the urls for the javascript to determine where it is being loaded from. If it stops showing tabs when not connected to the internet then it sounds like it is in fact loading them from google not locally.
I would put those custom settings in a user.config rather than directly in Web.config that way you won't lose the custom settings when you upgrade.
Make sure there are not multiple copies of these settings in Web.config, ones lower in the file will trump ones higher in the file.
Hope it helps,
Joe