Emax

Hello!! A couple days ago i have downloaded the demo disks from the 
emulator archive in emx format. Now the question is, some of these 
disks sounds perfectly when i put them in my emax II, but a lot of 
the banks sounds horribly and other don't even look to load in the 
emax.
Is this common with the disks of the emulator archive, maybe the pc i 
use don't write the emax disks correctly (note that a lot of banks 
works perfectly), any ideas??
Thanks a lot!!!!!