For a sputter system equipped with a constant current power supply and under reactive gas how control, certain compositions of film are usually not accessible in the normal steady states because;of the transition of steady state and the hysteresis effect. Theoretical studies in this article indicated that there exist abnormal steady states where films of intermediate compound contents may possibly be produced. However, the experimental endeavors to attain these states in a system under current/flow control failed. Further theoretical studies in this work indicated that not only are the abnormal steady states difficult to establish, but also they are sensitive to tiny drifts in parameter. In other words, in a sputter system with constant discharge current and constant reactive gas flow, the abnormal steady states can only be achieved and maintained when the parameters are set and kept in point sharply. These theoretical results revealed why it is not practically possible to operate steadily between the metal sputtering region and the compound sputtering region when a sputter system is under flow/current control.