Technically that ice cream (and other low fat / low sugar products) are perfectly fine as long as you can squeeze them in with your 'clean' foods.
Even when I am dieting I still hit some 'sinful' foods. For example, my post-workout shake must contain carbs so sometimes I will throw in 1/2 cup of normal ice cream in it.
The key for me is tracking everything I put in my body. (I love fitday.com) One quote I read a while back was "If it doesn't contribute directly towards by goals it does not go in my body." Rght now I am hitting 1800 calories a day wich consists of roughly 100g carbs, 250g protein and 44g fat - I'll hit the generic eggs/chicken/oats etc. diet but it will not kill me if I throw in a scoop of ice cream in here and there - especially on my cheat days where I allow myself to go up to 2500 cals.