ron johnson. now, ackman gets the blame for that. he was replaced this spring. now, some board members think it should be ackman's turn to leave or at least shut up. now, late word this afternoon, that jcpenney and ackman are in talks to resolve the dispute. >>> whether it's jcpenney, blackberry or dell. a company that was once the darling of wall street falls from grace. why does that happen and what are the warning signs for investors. we turn to bill george, the former ceo of metronix and professor of management at harvard business school. >> i'm sure this is a situation you've seen a lot, where investors don't spot the signs. that a company was a superstar, a company of stock gets into trouble. what are the warning signs, what slu investors look out for. and how can they guard against their investments. >> i think the first thing you have to look for is leadership. leadership on the cutting edge of technology and market changes. blackberry's a tragedy in the making. i've seen it coming for a couple years, the management was very parochial. i love canada, but