Tirst, thank you for the answers.
To Retroman:
Well, the default device in AmiCDFS' CD0 is: "scsi.device".
So, I can't figure out how it could work when WinUAE scsi device is called "uaescsi.device".
Anyway, I tried "scsi.device" and it didn't work either
By the way, I'm using with WorkBench 3.1 from Cloanto Amiga Forever.
I'm gonna try with Cache CDFS: is it really better ?
But I'd really want to use AmiCDFS