I've the RS-3 Lionchief Plus, delivered today, and it has the exact, same problem. It works in reverse, but jerks, hesitates, and sometimes stops in forward. The lights flicker in forward, but are steady in reverse. Very odd. After running in forward and stopping/powering down, it won't do anything until I manually move it or push down on the top. However, it operates 100% in reverse, never having a problem.
Dennis