MovieClips in library not attaching to stage

Recently launched this site :

the problem I’ve encountered on the home pg flash is that two big buttons and a bike animation should display prior to the photos loading. However, in firefox on both mac and pc(but not everyone’s) when you refresh the pg such that it draws from the browser’s cache, the buttons and bike animation do not display. Oddly, the photos still load consitently and in time as if those animations did take place. “oddly” because, the code to load the photos is part of an event listener, listening for the completion of the bike animation. So the code executes properly, despite the movieclips not appearing on stage(these movieclips are in library to begin and in my documnt class I instatiate them as follows:

        realtors_btn = new RealtorsButton();
        buyers_btn = new BuyersButton();
        bike = new Bike(X-150);

also, originally I had this same issue in IE, but after switching from swfObject 2.0 to adobe’s ac_runactivecontent.js method, I elliminated the issue in IE. Please help me, and let me know if I can provide more info. thank you!