I don't frequent the forums much but I saw a post from last year regarding duplexing and a Jamex 6557. Did you work it out? I didn't want to reply to it because the post was so old. Konica Minolta turns off duplexing when in key counter mode. I've had Techs tell me there is a soft switch to re-enable duplexing but I don't know what it is. I know Oce won't help you if you tell them it's a Jamex but the setting would be the same no matter what's connected.