Web Page wants to download

When using FF3 my web page wants to download instead of displaying correctly. I use IE7 and it works fime for me, but others have loading issues. In PMB I will give you the url for the site. 2 things - 1. I do not want a rewrite of my site - the pages are fine, minor errors I can live with. 2. The issue is server related, I know that by trying to add a simple page last night. I am looking for a viable solution by the bidder and then I will give the winner access to the server to adjust necessary settings. My site runs on a GoDaddy Virtual Server using a Plesk Control Panel, so, only bid if you know Plesk. You MUST state that in your bid or I WILL IGNORE IT. I will only accept $50 or less bids.