I took a quick peek at your site in Chrome (Mac OS 10.5 and Win XP) and IE 8 (Win XP), and the site loaded correctly. I suspect this may be an issue with the Flash Player on these particular browsers. Could you tell me:
1. The OS(es) involved
2. What Flash Player the browsers are running (see http://www.adobe.com/software/flash/about/)
3. If other Flash content is loading correctly in the browsers mentioned
It might help if you could supply a screenshot of the failed load too. I'm mostly curious about the point at which the load fails.