On my member page, next to License text I have that expires 12/19/2010 notification for my license key. Does that mean I have ordered that software just for 4 months and not for life time?
the first licence you get is just for a few months and then you are issued with the proper one, this is to protect against people purchasing amember and then claiming the money back off their credit card. you can contact amember support near the time the licence is going to expire to request a new one if they haven't contacted you themselves.