frameship cart quantity problem not working on all devices

hello i have a problem with my frameship cart. It doesnt work on all devices. For now i have discovered that it doesnt work on macbooks and windows 7. Basicly the quantity doesnt work + and - are unresponsive on some devices. and i i exit cart and add a new product the before product doesnt show up. Pls help it is a very big problem and i dont know what to do