My question involves collection proceedings in the State of: Idaho

Hi all. My question is concerning SOL and Abritration. Two years ago, my husband lost an arbitration for an MBNA credit card. The last payment that he made on this card was 2/10/2003. Two weeks ago, he was summonned to court, where the summons states: "You have been sued by the above-named claimant: The court may enter judgement against you without further notice unless you respond within 20 days". In my investigation, I found that SOL for written contract in Idaho is 5 years and Open-ended accounts is 4 years. My question is, when does the SOL time clock start? After the last payment made or after the Arbitration was won by the creditor?
Thank you very much for your help!