Well I am very happy to say that using the 68k version 4.2 of Poseidon -this one works sure in 3.9 so I did not try 4.3- my USB Deneb card works fine.

I also made the MOSNet to run adding the usbasixeth.device -USB To Ethernet- on the Interfaces file which is used by NetDB file.

So I am on line from my 4000 PPC / MorphOS PowerUP :)