ok so your not using cgminer are you? if you are then upgrade to the latest and remove those options.

how are you powering the stick? is it in a powered USB hub?

you say you have added a cpu cooler? does that mean you have added a cooler to the back of the standard heatsink or have you replaced the heatsink? maybe take the stick back to stock and just use a fan to blow air over it. see if that helps

edit. i just read you are using a 1.2M cable. remove the cable and try it. the power loss over a bad cable could be the issue.