Try getting Safari. That would probably work, cause it works for me. I have Firefox as well, but I have never tried to rate games using it as a browser.
Switch to explorer. Its very reliable and flexible.
I have found that most systems do not download well with explorer.. it also tends to update itself and restart your computer whether you want it to or not... but that's just my opinion.
Back to the topic at hand though... I use Firefox and have never had an issue rating, commenting or anything else on Armor Games... might it be a settings issue?