Thanks for the feedback.
I've fixed the Firefox problem, I've recently updated the site and had only tested using IE and Chrome. Firefox wasn't honouring the relative path of some of the pages because I had put a slash the wrong way around on the default page. If you try again, it should work although you may have to refresh the home page or clear the cache.
As far as the IE problem is concerned, are you using IE 64 bit, because that version does not support flash. All works fine on my two PC's using standard Internet Explorer. Try playing some youtube videos, and see if you get the same error.
Cheers,
Bernie