Volvo 850 starting problem - follow-up

1996 Volvo 850 GLT wagon (non turbo). This is my follow-up to previous post. Now I think its my starter motor, solenoid or the circuit, because the car is not turning when attempting to start. After few attempts it finally turns and starts. This only happens when the car is warm. However I am puzzled, because it starts fine on first attempt when cold. How can I check this. Could it be the ignition switch? The check engine light is off and the car runs beautifully when started. Would connecting the code reader give me any clues? Please help.

Adam