I don't know much about the A4000T SCSI, but generally both sides of the SCSI chain should be terminated. Use active terminators only. If your HD contains a passive terminator, disable it.
Terminator -> Devices -> Controller -> Terminator
I also have a cdrewriter but its on the 4000Ts scsi2 interface. Is it a better idea to use it on the CStormPPC`s SCSI?
Yes! It is a lot faster, for one thing!