Sub con placed lein on home. Owed $ by contractor now out of business. I paid in full. Job completed in April. What do I do now?

Subcontractor has sent a letter of intention to place a lein on my home as he was only paid by the contractor for 50% of the work done on my home. He is still owed $3,105. Date on his contract with the contractor is Nov. All work completed by 3/27/09. I paid contractor in full. Contractor appears to be out of business-phones disconnected, email suspended. I never had any contact, written contract or previous notices from the subcontractor until now-4 months after completion of all work. Contractor was licensed and bonded. What do I do now and does this subcontractor have the right to more money from me since I paid in full? I live in the District of Columbia, contractors address was in DC, subcontractor is in Maryland. Thanks-Leslie