@recman012 - the Events Manager plugin may be broken when used in conjunction with some themes. This not only breaks the AJAX listener for Store Locator Plus but will break most any other plugin or theme using AJAX. In fact I had 3 different test themes that would not work properly with Events Manager turned on, though they are all Theme Forest based themes.
The common error message between all the themes & the Store Locator Plus AJAX hooks (WordPress AJAX listener) is:
Notice: A session had already been started - ignoring session_start() in /home/wordpress/wp/wp-content/themes/rttheme17/functions.php on line 9
While this particular error cites RTTHEME17, it may be a red herring. Change themes and the message changes. Essentially Events Manager will break ANY theme that uses any kind of session management (most themes? not sure on that).
I would write to the Events Manager people and/or your theme people and find out why sessions are breaking. Since the Twenty Ten / Twenty Eleven themes work with Events Manager you will likely get into some finger-pointing, but it is obvious Events Manager and any themes using sessions (especially Theme Forest based session management) seems to have problems.