W appeals an order which denied her motion to set aside a Mediated Settlement Agreement in a divorce action with H. After denial of her motion, the Mediated Settlement Agreement was incorporated into the Final Judgment of Dissolution of Marriage. The judge based his decision on the rationale and factors enumerated in Casto. There are essentially two separate grounds for invalidating pre- or post-nuptial agreements. The first deals with fraud, duress, coercion, misrepresentation or overreaching. The second is 'unfairness.' Unfairness involves an agreement which makes an unfair or unreasonable provision for that spouse, given the circumstances of the parties. The trial court, in following Casto, found there was a presumption of concealment or a presumed lack of knowledge. It then found the presumption was overcome because W was sufficiently aware of the marital assets and income of the parties. The agreement, in this case, is a mediated settlement agreement concluded through the expertise of a trained and certified mediator and in the course of a contested dissolution proceeding.