On a recent taxi ride to the airport, a Twin Cities woman noticed that the meter started near $6. After reading postings in the cab, she realized she had been charged the normal startup fee, but also an "airport use fee." "The [$4 airport use] fee is only collectible by taxi companies that are permitted by [the Metropolitan Airports Commission], and the permit is for picking up at the airport, not for picking up anywhere else," airport spokesman Patrick Hogan said. At the end of the ride, when the woman confronted the driver, he verbally reduced the fare by "a dollar or two." She later called the cab company. "I was told "oh, they make that mistake sometimes,'" she said. So she contacted Whistleblower. "This little 'self-tip' should stop," she said. "It's not a lot of money, but it is also not right." Have you encountered the same problem?