No denial yet, from Amp'd Mobile, about the exit of the mobile operator's "visionary" founder and chief exec, Peter Adderton, a rumor we floated yesterday . So here's another one: that the cellphone marketer, despite raising a reported $360m from investors such as MTV Networks and Redpoint, faces a cash crunch. A Valleywag tipster suggests the company owes as much as $100m to Verizon, whose network Amp'd rents, and other creditors, and is short of liquidity. Which is confusing: Amp'd, which targets tech-savvy 18-35 year-olds, raised its latest round in March , according to filings. To be sure, the cellphone retail business is expensive, and Amp'd, which had 100,000 subscribers at the end of 2006, needs several times that before it can be profitable. But how on earth could the company be running short again, already?