Finding surf features at wrong location

I am doing image processign with surf feature extraction algorithm which works better when we apply it on different types of objects to detect. But when i apply it on similar behaving images like keyboards or switches it detects and extract features at similar objects on the other keyboards. for example i want to detect two keyboards( I and J ) so the features of image I was founded on J because of its similar behaviour ? I need to eliminate it and detect the correct images .Please help any leads will be eappreciated. Thanks in advance