Hi,
I'm not able to copy on WD MyPassword files bigger than ~400mb+, Ambient tell me there is a problem with filesystem.

I've formatted my hd with FAT32. I'm not able to test it from usb because seems pb doesn't give right power to all hd usb (in fact I've another hd usb with double usb cable, and if I connect all two them then hd works, if I connect my hd with only one usb then it doesn't work).

Obviously from Windows WD MyPassword using usb has not problems at all.

It is known fact that PowerBook USB does not provide enough current to power external USB hard drives, so you need to use a powered USB hub to connect the external hard drive to and then connect the hub to your G4 PowerBook.

That is the only way I have been able to use an external USB hard drive with my PowerBook.

Sure, but my WD MYPassword HD is provided even of as firewire port, in fact my copy problem is possible to be of helios stack because I use FIREWIRE port with MorphOS (not USB one), because if I try to copy from Windows using USB I've no problem at all...