Keyboard And Tascam US-122 ?

[Bucks]

I have a version of Cubasis that came with the Tascam US-122. I installed it's software on my G4 Mac tower running 8.6. I also installed OMS from Opcode site as instructed in manual. Then I installed Cubasis sucessfully. I want to use this with my keyboard. The Tascam US 122 shows up in my control panel but when I try to open Cubasis I get a message that says there is no Tascam interface. Can you please help me. Tascam is saying it's not their problem. I've been working on this for days. Please, please help
Thanks
Buck