Every time i connect my TT XXL 540TM to my laptop (windows Vista ) a message box comes up saying "there might be a problem with some files on this device or disc". It asks me if i want to "scan and fix" or "continue without scanning". Im wondering why this happens and if this is a sign that something is wrong with my TT unit ? The unit works fine, havent had a problem so far. Also it has the latest maps and software.