Hello, I just purchased a "new" Nike+ sensor kit off of ebay, but upon receiving it today, saw that there were noticeable scratches/scuffs on the sensor and transmitter. When I plugged the transmitter into my ipod nano, the readings displayed 0 miles (although It may not be difficult to clear one's running history). How would I check how many miles are actually on this sensor or the battery usage assuming that the data has been cleared and the sensor used? Hope someone can help - I am new to Nike+. I hope I haven't been taken for an ebay ride. Thanks.