Google (GOOG) published the latest Android distribution numbers on Tuesday and the results display Android‘s number one problem — fragmentation. The latest version of Google’s operating system, known as Jelly Bean, is still only found on 13.6% of all devices, a slight increase from 10.2% last month. The adoption rate of Ice Cream Sandwich remained flat at 29%, however, and nearly half of all Android devices are still powered by Gingerbread. The two-year-old operating system’s share of the market only dropped 1.2 percentage points from 46.6% to 45.4%. Fragmentation remains a major issue for Android and Google, and the latest numbers show that the company must continue to work with carriers and manufacturers to ensure older devices are being updated to newer and more secure versions of the operating system.