As far as I know, there should be zero play when the lock is engaged. It could be that a washer is missing. If you are good with tools and are confident that you can take your knife apart, start to take the pivot out and see if it does have the washer on either side. That would be my first suggestion. If you are not confortable taking the knife apart, send it in as forcedstrike suggested. Benchmade will take care of you.