Gonna toss my thoughts, may be totally wrong. First thing that comes to mind, are you using a Sharp hook? Make sure those hooks are sharp, second, your hook has not been bent at all from hanging up in trees and stuff? is your rod to limber to properly set the hook in that depth of water? Maybe a lot more stretch in your line then you think? just a couple ideas that come to my mind. I am sure some experienced guys will chime in.