Vonage's post-IPO troubles must be weighing heavily on the shoulders of chairman and co-founder Jeff Citron. For the second time in two weeks, he gave a keynote at a conference that lacked any kind of sizzle. Brian Ward said Citron's speech at Convergence 2.0 failed to address any of the issues facing Vonage these days (growing criticism about its marketing spending, class-action lawsuits, discounts for subscribers who threaten to leave, etc.). With Vonage under siege, this is a time when you'd expect a marketing-wizard such as Citron to creatively and enthusiastically come to the company's defense. After all, he co-founded Vonage because he believed VoIP would be a disruptive technology. What happened to that chutzpah? Now that Vonage is public, itseems like Citron believes he has to behave. But if all you're going to do is give tepid keynotes with no meat, why bother talking at all because you end up doing more harm than good? One other thing, Citron declined to answer questions after his keynote. Strange because it's not like he's not good at avoiding questions he can't answer.