Glad to hear you got it sorted out! Thanks for the props, too, but it was good perception on your part to discover the problem in the first place. Improper valve alignment will do bad things even to a very expensive horn. I have a Bach cornet that shut down in the upper register and it turned out that the valve alignment was way off in the open position. Now, that's harder to tell, because you can't look down the valve tubes and see it. Anyway, the local shop had a tool for measuring the "up" alignment and some thicker valve felts made the horn play like it should.