Filed under: Cellphones, WirelessAs with RIM's April 2007 outage, the latest downtime has been officially blamed on a flawed software upgrade. According to RIM, the millions left without email can lift their kinked neck and point a crippled digit at an "internal data routing system within the BlackBerry service infrastructure that had been recently upgraded." This upgrade, like the one in 2007, was meant to boost capacity and speed message r