Microsoft CFO Amy Hood. Stephen Brashear/Getty Images Microsoft missed earnings expectations by a couple of cents per share on Thursday afternoon because of an unexpected tax adjustment that skimmed $0.04 off its earnings per share.

In the release, Microsoft noted that its patent-licensing revenue was down 26% from a year ago. And it's because of Android.

Android phones are still selling just fine, but the market is dominated by cheap handsets being sold in developing countries like China and India.

"The mix of devices in that market has shifted to the low end," said Chris Suh, Microsoft's head of investor relations.

Microsoft's cut is also sinking.

Suh also noted that not every Android manufacturer has a licensing deal with Microsoft. He didn't name names, but Chinese phone makers typically take a very loose approach toward licensing American intellectual property, and as those inexpensive phones take over the world, Microsoft doesn't benefit as much.

At one point, Microsoft was reported to be booking $2 billion a year from licensing its patents and other intellectual property to Android handset makers like Samsung and HTC. Microsoft has never confirmed that number, but it's probably a drop in the bucket compared to the overall Windows business, which booked revenue around $4.2 billion this quarter. ("Windows revenue decreased $292 million or 7%," the release says.)

Still, the Android gravy train is slowing down for everybody.