Janie - as I understand it, if you are taking in extra calories, no matter the form, your body will turn it in to fat. I don't see how extra protein, if you are under calories, would turn into fat. It could be wasted b/c you can only assimilate so much protein at a time though. And I would think it would depend on what is in your protein powders too as to how your body stores those calories.
Baylian - what kind were you drinking that gave you the gas?? I totally stay away from soy proteins and whey protein concentrates can cause it if you have a lactose problem but the isolates should not cause such an issue.