On my A3000 with AmigaOS3.1 and PC0: loaded, the disk drive will spin, bring up the two icons, freeze the icons (can't do anything with them) and then the light on the drive stays on - rendering the floppy useless. Without PC0: enabled, the disk drive is fine in Amiga mode.
I've used CrossDOS and not. Made sure the tooltypes were correct for PC0: as well. Something wrong with my disk drive you think? External 1010 configured as PC2: works fine - so I'm thinking something is up with my HD DF0: drive. Maybe a jumper is misconfigured on the back?