I agree with Tommy…I have a different brand than you two, but have not had the experiences others have related with false readings. Reason being, I have been extremely careful and smart with it. I have never eaten or drank anything in the car, except water. Never used mouthwash, or any of the other things people mentioned that cause them issues. Read through the forums and see what people say has caused false fails, and simply avoid that. Just use common sense and you’ll be fine. I’ve had mine for a year and am due to get it off on Monday(!), it could be a lot worse than the six month term you have.