Netserver LH4R / Storage Rack

[CA1281591]

Help... I have just acquired a LH4R 4 x 500 PIII XEON machine. I have built it with 6 drives. The first drive only has the O/S = Windows 2000 Server. The remainder have been configured as Raid 5. (The are all 18g drives).
These configuration is working fine.
The problem is I also have a rack of 8 x 18g drives that I am trying to connect. I have tried using different SCSI cards Adaptec 29160 etc, a IBM raid card. Both of these only identifies that two drives exist.
When powered up I go into the computer management tool and sure enough there they are.. why aren't the others being identified.. what info do you require..??