Internet Explorer 10.0.9200.16540. And now I make a comment, save, hit refresh and it doesn't display. Now to see if a) this doesn't show either or b) when I save it BOTH turn up.
OK, I am now logged in from Internet Explorer 10.0.9200 and it works. It also displays a lot of ads that I suspect NoScript was blocking. Did you, by chance, get this as a freebie with some of the adware or trackware? Seems unlikely it would not work with anything as common as Firefox. No biggie - I don't usually have much to say anyway.
Next time arrange a party floor with the hotel ahead of time, and make sure the guests therein are those holding parties, and those attending them or at least not bothered by noise. Of course your con has to be big enough to assure you WILL have all the rooms on the floor (and preferably the next floor below...)