hey guys wonder if you can answer a question for me? I shoot a Martin cheetah I know this is not a high end bow but it more than supports my needs. I practice almost daily and believe my form is consistent. When I pull my bow back it will pull back easily but the next time it will feel like I increased the DW by about ten pounds. I let off pull back again and feels right again I make sure I pull back exactly the same every time. This happens whether I have shot 2 arrows or 30.Any idea as to my problem?