White squares on my prezi @ presenting mode, works fine @ edit mode

Hi, There are white areas on my prezi when presenting (without logging in). Everything looks fine when editing, even presenting in edit mode.
Is this is a resource limit I reached, or something? It was frustating it showed up only when actually presenting my first prezi :( They persist when zooming in.prezi See my prezi @ /user/zoltankiss
Thx!