CP 7 Bug? Long delay between preloader and first slide

I am using OSX Mavericks 10.9.2 and recenly created my first project since upgrading to CP 7. My project is 15 slides and contains only audio (mp3) and image files. My preloader is set to 25%. When I upload the published project to my web server and test, there is a fairly long delay after the preloader loads and before the course begins. It last several seconds and appears as if all the elements on the first slide are missing (the only thing that shows is the playbar - I have only the CC button turned on):

Is this a bug with CP 7? I have never experienced anything like this in CP 5.5 and 6.