Perk Valley school teachers have rejected a fact finder recommendation for a settlement in their  contract dispute with the district.   The school board has approved the proposed agreement and the teachers could vote on it again.   If they reject it twice or don't vote a second time, a third party mediator will resume efforts to negotiate a contract.   The fact finder report turned down by the teachers included average raises totaling almost $6,600 over the life of the proposed three year deal.   The teachers have been working without a contract since the end of last August.