my device give me false positives quite often. some in the morning & i'm not sure why. Last sunday (june 6) on my lunch break i passed the initial test right away. between that & my 2nd test i ate Ben & Jerrys Thick Mint ice cream with nothing to drink. i failed the retest. because of ice cream. its also happened with peanut M&M's & coke during a lunch break. some mornings (like today) i had nothing to drink & eat in the morning but i still failed. i keep getting constant extension on my lease because your device sucks. your company is a big cheat.