I had trouble after PBP 2003 and the numbness in my right hand went after a month, but the grip with my right thumb was still weak and it was in the December when lifting a pint of beer my thumb clicked and it returned all of a sudden, our pub diagnosis was that a tendon clicked back in to place and resumed the correct leverage mechanisms required.
I had no such troubles on LEL 2005 but I had prepared with more miles and used 'Specialized Bar Phat wrap' and the BG gloves, I was also more aware of shaking out my hands more often to relieve the circulation.