When I had my interview on 9/21 the agent noted that sometimes if your hands are too dry (as would be the case when flying on a jet) the fingerprints may not appear with the correct clarity--his suggestion was to wipe your fingers on your forehead before scanning them, as this will add a bit of moisture, has anyone else been told this during their interview?
Nope, but it happened to me at the IAH kiosk.