I own a Yahoo group. But when I log in, I can't access the options. Help!!?

I and at least one of the two moderators of my group have not been able to invite new members because the "invite" option that should be in the light blue side bar on the home page for owners and moderators isn't there and we can't activate the "messages", "files", or "members" options, even though they are listed on the home page. What is causing these problems and how can we solve them!!! Help!!! Judith Rooks, Owner of health.groups.yahoo.com/group/N2Oduringl…