my contact page form was ok too, i think it has to do with a conflict between the field names or something. My theme is pulling things from everywhere, TMs coding really sucks.
do you use Firebug? download it like elames said, it will show you exactly what CSS is being used for anything you want. find what its using in what files, disable and enable one by one. if all else fails, another option is to by a template from WooThemes so you have access to support there.
and for the record again, Template Monster sucks *LOL* I hate editing their crappy code.