I have an expensive Japanese market Elecom Thumb ball. It is acting up and I do not know what is wrong. It gets very slow. I clean out the ball cavity, not touching the sensor window with a towel. It is then fine for about 15 minutes. Then back to slow again and I must wipe it again. Please do not tell me this is gone! Since this was Grey market JDM it cost me a lot and of course I have no warranty on it. If it is damaged hopefully someone can help through fixing it. Thank you
