Arctic Startup has been digging into the finances of Angry Birds publisher Rovio, and has uncovered a hole – a $42m one. The company raised $42m of funding in March 2011 from Accel Partners, Atomico Ventures and Felicis Ventures, saying it “will give Rovio wings”. Strangely, though, it’s missing from the company’s financial results for the year. “When a round of this size isn’t visible in the books of the company, it must have gone to one or more of the owners of Rovio as the new investors came on board,” notes Arctic Startup. There’s no scandal here – more intense interest in how Rovio is going about its business, and what it means for any future acquisition or IPO.