[DCRich]

Try connecting the arm to a pwm port with an address less than 9 (ie. 1 to 8). I have not personally used so many motors in the past but the schematics show that channels 9 and 10 are wired slightly differently than 1 - 8. You should try using a higher pulse duty cycle. Finally check to make sure that the black wire in the WRB cable is in the correct position. Victors allow the wire header to be inserted backwards.