The valves on both my Bb and C Xenos seem extremely unresponsive and prone to random hang-ups. I've never had this problem with any other horn I've played, and none of those were Xeno. I was talking to someone who plays Bach today and he played my Xeno. The first thing he said was "wow I hate Xeno valves." Have any other Xeno users experienced this? I'm starting to get frustrated because the horns play great it's just the valves!