gugucom's suggested an idea (here, start at post 34), as it seems a couple of members may have done it.If you buy a sata optical drive and convert the connector to PATA, will you lose native sata speed?? I am now seeing that it is not worth it to buy sata optical drives for 2006-2008 mac pros because Apple ****ed up the firmware!!!!!!!!!! DAMN APPLE!
YES, I AM EXTREMELY ANGRY ABOUT THIS!!!!!!!!
Go SATA only. Pull the IDE drives, and use a SATA optical on one of the ports, and a SATA HDD on the other, if you wish to do that. As I know you want optical, get the SATA optcal drive, and pull the IDE cable from the IDE optical drive, and see if that works.
That might be just the way to get around the IDE-SATA interaction on the optical drive port issue in the firmware.