Process of elemination!
Your shafts may be either to stiff or to weak.
Suggestion: Get a nice variety of different tip weights above and below 225 grains, and play around untill you find your sweet spot. If you have to add to much weight you may have to drop down to 3555's.
Your brace height may be either to high or to low.
Suggestion: Call maddog archery and find out where the minium brace height is. Coordinate this suggestion with the one above.
Could be your release.
Suggestion: Make sure the first two suggestion are addressed, and then watch your release. Make sure your not plucking the string. Watch Moebow on youtube.
Hope this helps.