Filed under: WirelessThere's a bit of a mystery emerging on the 700MHz auction front. Frontline Wireless, which has made no secret of its desire to bid and win on the D-block spectrum, has a released a statement saying "Frontline is closed for business at this time. We have no further comment." At the risk of stating the obvious, we'd say that it's a rather inconvenient time for the company to be "closed for business," and this could spell doom for the company's efforts in the 700MHz auction -- or not, there's really no way to tell at this point, and Frontline's industry connections run deep, including a sketch