Forgot about this part. The submit button refuses to work? I haven't heard of this happening... we're not doing any funny business with the submit button besides validation.. you're not getting any error messages when this happens? Any consistencies you can mention when it happens? Always in Firefox and not IE?
Broken spell checker - We don't have a spell checker on the control that I know of so it must be the Firefox spell checker you're referring to? In what way is it broken?