Emax

I made some Emaxos Floppys with EMXP and Omnifloppy, when i put them in the emax it says: "Disk Not Formattet!" and with some other Disks: "Disk Error!". 

I use DSDD Disks and an PC with xp and internal drive.
The emax is a standard rack version from 1986.

Is there anything/ trick i am missing?

cheers k