Several icecream producers,including industry giants Cold Stone and Dairy Queen,say they have improved their management procedures after inspectors found an excessive level of bacteria in their products.The Shanghai Costomer Rights Protection Group said yesterday it had spot-checked 22 icecream samples in June and found that ten of them contained higher levels of coliform bacteria than allowed.Experts say reasons may have been substandard freezers,improper staff operations.Some stores say they have installed bars over their counters to block bacteria,and now check their freezer temperatures every tow hours.