windsaver problem maybe on chromatic

Hi Kinya

I had a one-day stopover in Hong Kong last week, and couldn't resist the urge to buy a Sirius 56 for much less than it costs here in France.  After playing for about a half hour, I started getting a bad kind of stutter on the 1-hole blow that eventually went away.  I didn't take it back to the shop because I couldn't reliably reproduce the problem and, besides, they only had that one example in stock, and it sounds fantastic otherwise.  Back home, I thought the problem might have been solved, but it comes back every time I play (then goes away).  Sissi Jones describes something that sounds like what I have elsewhere on this site, but what's weird is that it always affects the same note and no other.  I took the cover off and everything looks fine.  Do you think I should just change the windsaver (and would you know who in Europe might sell them?)

Thanks!