when mine does that, it can be one of two things. You can try and trim your reed just a little, or file the back of your insert. Don't go wild with either. If you trim your reed, don't take off more than 1/32 of an inch at most, less is better, you can always cut a little more off. When filing off the back end of (the curved part) of your insert, you will be suprised how little it takes to make a BIG difference. 3 or 4 light strokes with a mill smooth file on the last 1/3 of the insert will let you know if your headed in the right direction. Once again, you can alway file a little more off if needed, but it is real hard to put it back on.... ;D