Hi. I play a 64 10m that I absolutely love but I have one small issue with. Sometimes when practicing if I play an A2 (and sometimes Bb3) I get sort of a faint "distortion" in the sound, like the lower octave is trying to speak VERY faintly. When this happens if I take a pipe cleaner and push it up thru the octave key vent it seems to go away for a while, but it will eventually return. It also seems that if I play the A2 without the octave key I don't have this problem, so I 'm pretty sure it's something in the octave key vent. Since of course this horn has an underslung octave key, is it possible that something is sometimes lodging itself in the vent, partially closing it? I should note that this bothers me the most when practicing, doing long tones etc. Any ideas? Thanks!