Changes in high ranking positions aren't always good. Unexplained changes in high ranking positions are even more suspicious. Given the suddenness of the move and the circumstances revolving around it, Lenovo's announcement that mobile business head and Motorola Mobility chair Liu Jun is stepping down is sure to raise a few eyebrows. In his stead will be Chen Xudong who leads Lenovo's ShenQi, another and separate smartphone unit in China that sells devices online. All of these just after Lenovo's rather positive performance in the smartphone market.