Something else to keep in mind, is that the body can typically only absorb X amount of protein at a time. Find you a protein powder with a fairly high protein per serving ratio, and give it a shot.
The problem is that if a label says 25 grams of protein per scoop what they really mean is 25 grams of varying quality of protein powders per scoop which usually averages out to be somewhere aroound 50%, so your actually only getting about 12.5 grams per scoop. Another thing when they say 100% whey isolate they often mean that the isolate in it is 100% whey isolate but they may be adding concentates of various qualities.