Silicon Valley Insider points out this morning that Oprah — after making her grand debut on Twitter two weeks ago — hasn’t tweeted in four entire days. In her most recent tweet, which came last Friday, she asked popular helicopter-jumping Wolverine star Hugh Jackman out on a dinner date for tomorrow night, before his appearance on her show this Friday (“Hugh … I’m countin’ the hours. Wanna do dinner the night before. Same booth? Or catch up fresh on the air”). Jackman accepted: “Dinner Thursday night, our same booth would be perfect.” But then he tweeted, cryptically: “I am going to work on getting to Chicago sooner. Cannot wait … ” And now, for nearly a week, Oprah’s been too exhausted to tweet. We wonder what happened!