I am able to view your website and the calendar. I does not have any events on it. People are able to see my calendar but the busy/unavailable info is not correct for unit 238.
The message that I sent you was from a work calendar that is restricted I think. I run XP Professional and parallels on my Mac. When I go to my website on it the calender is not the same as when I look from my Mac and Firefox.
My webpage with the calendar is
Try the URL for the calendar in the browser...
That's the one that's in the iframe code on your site. If the info on the calendar is not correct, you need to change the calendar - not the code on the web page.