Microsoft had over a billion reasons (per year) to pursue a patent licensing deal with Samsung back in 2011 over the latter's use of Android. That fact is laid bare by a lawsuit today over the interest on payments (based on the number of Android devices sold) that are supposed to flow from Korea to Redmond. Re/code posted the unsealed lawsuit this evening, showing how despite the existing deal, Microsoft's purchase of Nokia last year lead to Samsung holding up its payment for the second fiscal year of the deal, and then refusing to pay interest on it. All of that is according to Microsoft, which also claims Samsung is threatening to hold off on paying its end for the third year of the seven-year deal.