[daveT]

I think that most flop mistakes come from pre-flop mistakes. If you are varying your PF raises, then you are creating two problems:

Big pots are too hard to get away from.
Even calling stations have a brain.

I think that you are probably playing too tight, limping too much, raising too much with obviously strong hands, etc. I am not saying that these are all your problems, just food for thought.