Diehard BlackBerry users often compare BlackBerry Messenger to a potent drug. And just like a drug, coming down from a BBM high can be rough -- so rough, in fact, that RIM's claiming that a couple recent releases are responsible for "an unanticipated database issue" that stone-cold knocked out data service for many of the world's subscribers yesterday. Folks using versions 5.0.0.55 and .56 are being strongly advised to upgrade to 5.0.0.57 immediately, but in the meantime, Waterloo says its systems are back to normal while apologizing "for any inconvenience to customers." With three major outages now under BlackBerry's belt in the past month, faith in the rock-solid stability of its infrastructure is fading rapidly -- but then again, it gives you a great excuse to be off IM for a few hours and talk to live humans, doesn't it?