Not sure if I can help but we are running Macs on a network. We have a HM-1
DTG printer which uses a PC RIP. We had some issues getting our Macs to talk with the PC but now have no issues. It is more of a permissions issue I think. Are you running OSX and if so what version. We switched over to 10.5 and had all kinds of issues right away. After much hair pulling I found we needed an update to the OSX software to repair some permissions issues. This seemed to clear up our problems. Running Macs and PC's in the same network is always a problem. We have been using Windows servers since the beginning since no Mac servers were available at that time. I must admit though, our Windows 2000 Server software is pretty stable. It runs 24/7 and only shuts down when we have a power outage. I don't know why you would need any additional software since OSX is more friendly to Windows than ever before.
I think you need to call your RIP software help line to see if they can help. Good luck though. It seems we are living in a PC world but that's okay with me. Let the PC users get all the viruses, I'll take my Mac any day.