JSON memory leaks iphone sdk

iPhone app is getting slow while tes开发者_运维技巧ting in the performance tool,but it works fine while simply build and run on the device.I am getting following leaks:

1. [NSCFString CopyWithZone];
2. [NSCFStringAppendString];
3. JSON Parser : [SBJSONParser ScanRestOfDictionary];

Basically.what i get is the leaks are coming while using JSON Parser because data is load from server in the JSON format.2