Offhand, it sounds like something I see on a few web pages. A few web pages don't work perfectly on all browsers. Usually, this means they only work perfectly on Internet Explorer, as that is the browser that the developer of the web page most likely tested against. The page will mostly work on other browsers, but some key feature will be inoperative.
I don't use Delphi, so I am not seeing the particular problem you describe, but I see this on one of my online banking pages, where one key Submit button is inoperative (which is annoying after I just spent a few minutes filling out a fussy form, and then can't Submit it ;).
Authoring complex web pages is a difficult task. There are a zillion different browsers and browser versions out there, and some of the more complex aspects of displaying web pages in a browser are by no means adequately standard across all browsers. A place like Google, Yahoo or Amazon spends millions of dollars making sure that their fancy web pages display and work correctly on a wide range of browsers. It can take some really ugly looking hacks to accomplish this.
All browsers other than the most popular (which is clearly Internet Explorer) will be affected by this, as the risk of something not working right is always greater for the less well tested browser.
The ones to complain to are Delphi Forums -- tell them what is not working on Firefox. Though to be honest, I've never had much luck doing that with the problems I've encountered running other (non-IE) browsers. So I keep a Windows system handy so I can run Internet Explorer for those web pages I care about that don't work well enough in my preferred setup of Firefox on Linux.
I can open IE (7) without add ons also and that also seems to solve the problem. Other then this one error message i really don’t see all the fuss about Mozilla being so much better then IE.
Do you think it is?