I just got my Buffet E11 3 days ago and it played very well.Ive been very good with it, Swabbing,cork grease,and polishing it.All of a sudden I wake up this morning to play with it and the low C# is stuffy!The high G# is fine but its just the low C#. I tried to check for cracks but dont exactly know how to find it. Please help, I have to decide whether to return it in 4 days and wait for a new one, or figure out what is wrong with it now.Help Please!