Additional information is needed in order to answer this question. It is unclear exactly what the agreement is for. Also, there should have been a property disposition done when the dissolution was finalized. Please consult with an experienced attorney in private so that additional details can be given and the documents can be reviewed. Many attorneys, including myself, offer free inital consultations.
It all depends on what the documents say. You should set up a one hour consultation with an attorney in your area and bring both the community property agreement and the final divorce papers to them to review.