I have seen people pack so much stuff in their case that they are actually putting stress on their horn. sounds like you either have something bouncing around in your case or you have to much stuff crammed in your case. I hope you aren't using a gig bag. good luck on figuring out how your valves are getting messed up. I know of cases where someone put to much stuff in their case and it was pushing on the second valve slide and causing valve problems.