are you defrosting them first? I eat them and frozen raspberries everyday in my oatmeal, cottage cheese and Fage. With the Fage, however, I'm including chocolate protein powder and some Stevia. I really like to take about 1/4 cp of berries and heat them in the microwave for about 45 seconds, then dump them in my oatmeal for breakfast.
They'll never be as good as fresh, of course, but we only have maybe 2 months out of the year where you don't need to take a 2nd mortgage out to buy them fresh.