wasq  is correct.  Use the 
www.ahevents.org url and you will only have to login in once.  When you go to 
http://ahevents.org and click the login button a window pops up which allows you to login.  This login is done via a cookie / session var being set.  The cookie is being set to ahevents.org.  When you click on another link in the menu, it changes your web url to 
http://www.ahevents.org/... which the cookie / session tag no longer is valid for.  Thus causing you to have to log in again.