Help DVD Duplicator and Firmware for Burners

I just got an A Card 3 dvd controller and I have purchased 3 dvd burners two are Liteon SOHW-812S and the other one is a LiteOn LDW451S. Now I have upgraded all the firmware from this site. However whenever I try to burn only two burn. The third never burns. I asked the company I got it from and he said that with the ACARD all the burners should have the same firmware. That makes sense but the two that burn are not always the two LiteonSOWH-812S which has the same firmware. Sometimes its one of those and the LDW451S which has a different firmware upgrade. Does anyone know anything about dvd duplicators and if this is the case. I am trying so hard to figure out why only two works at a time. This is a brand new controller card and the second one I have gotten and I still have the same problem.

I was always led to believe all writers must be identical in order for it to work

Odd, perhaps it’s losing track of which the two identical drives are - might be worth taking them all up to Codeguys CG3B … the 812S to 832S and 451S/851S to 832S versions.

NB. They are NOT identiacl in -R, as the upgraded 451s/851S lacks 8x -R support, so if a -R burn is attempted, it would need to be at 4x.