About 3 month ago I got myself a 928 Sovereign cornet (demo model from the store). Valves are smooth and fast, much improved over my 923 Round Stamp. Cleaned the instrument twice since I got it to get all the gunk out of the instrument which sometimes is left from the manufacturing process. However, after about one week of playing the second valve can sometimes get a little sluggish. Never had that issue with my 923. Just wondering if that is part of 'break-in' and the instrument needs a little more time to 'loosen' up OR does it need some 'medical' attention? Using Fast valve oil.