Last we heard about microblogging service Twitter's latest funding round, Union Square Ventures partner Albert Wenger told us — and, via Twitter, the world — that he was taking a lunch meeting at Twitter HQ. That was April 25. Despite rumors of an imminent deal, there's been no announcement. So why can't Wenger and his USV partner Fred Wilson close the deal? One theory: an unexpected bidding war over a service that grows more mainstream every day. A source familiar with this type of funding situation explains: "You know that thing about failure is an orphan, success has a million dads? VCs want to buy the right to say Twitter was theirs." And for this crowd, Twitter's downtime problems are a bonus.

Someone carefully let it be known today that Twitter cofounders Evan Williams and Biz Stone are looking for $15 million in venture-capital funding. We emailed existing Fred Wilson, a partner at Twitter investor Union Square Ventures, to ask if Twitter's been in touch, looking for a re-up. Wilson's unresponsive answer: "Yes, Union Square Ventures is an existing investor in Twitter." Lucky for us, Wilson's colleague Albert Wenger isn't nearly as discreet. He Twittered about his destination for lunch: Twitter headquarters.

Twitter, a communications tool for marketers, self-promoters and journalists, is trying to raise a third round of venture capital Silicon Alley Insider reports cofounders Evan Williams and Biz Stone are looking for $15 million, valuing the company at $60 million. Current investors include Union Square Ventures and Charles River Ventures. SAI guesses Stone and Williams have pitched Spark Capital, too. Twitter raised $5 million for a $20 million valuation last summer. The company still hasn't found a business model, mostly because users, by and large, view Twitter messages on cell phones or third-party desktop applications, not the Twitter.com website. We find this endless groping embarrassing. Twitter limits messages to 140 characters. Why not shorten it to 120 and slap "Sponsored by Coke" to the end of each message? That seems easier.

When Twitter hired Lee Mighdoll as VP of engineering and operations in January, cofounder Biz Stone called him the "perfect match" for the company. Not anymore. Mighdoll is out after just three months of the job. "The match was not perfect," Stone told SAI in an email. Mighdoll is the second engineer reported to have left Twitter in the last two days; architect Blaine Cook fled the country yesterday. Neither was able to fix Twitter's oft-reported propensity to crash. We hear the final straw to break Biz Stone's back was not the breakdown yesterday that TechCrunch described as a "privacy disaster". Makes sense, because isn't that Twitter's raison d'être?

Twitter cofounder Biz Stone once said, "There will never be ads on Twitter.com." Note that Stone never said anything about Twitter.jp. News.com reports that Twitter has launched in Japan, with ads. "Ads are important," Twitter backer Joi Ito said. "It's always harder to add ads later. So we're launching with them in Japan." What a tiresome PR game: Are ads any less important in the U.S.? If Stone wants to add them to Twitter.com, he and cofounder Evan Williams should go ahead. The ads in Japan actually link to the advertiser's Twitter feed. WIth that kind of arrangement, Robert Scoble and Jason Calacanis will surely sign up as charter sponsors.

Ads on Twitter? They already exist — just not where TechCrunch's Duncan Riley thought they appeared. Twitter cofounder Biz Stone denied Riley's report, telling Silicon Alley Insider, "We're not putting ads on Twitter.com" — meaning Twitter's website. Of course. That would be the stupidest imaginable place to put ads, and Stone knows it. Which is why, for almost half a year, Twitter has been running ads elsewhere.

Twitter experienced a serious bug tonight — one that had users logging in and sending updates as other people. It wasn't hacked, as some suggested. Cofounder Biz Stone initially described the problem as a "timeline oddity," and then fessed up: He'd rolled out an update to the microblogging service that didn't work. What I'd like to know: Does it really matter? This sounds way more fun than regular Twitter.