I've been doing a bit of research into why my Casio QV-3500 camera won't 
work under
NetBSD after I found out it did work with Linux. Here's what NetBSD reports:

umass0 at uhub0 port 1 configuration 1 interface 0
umass0: CASIO QV DigitalCamera, rev 1.00/90.09, addr 2
umass0: using ATAPI over CBI
atapibus0 at umass0 channel 0: 2 targets
probe(umass0:0:0): generic HBA error

A dig around in the Linux kernel source reveals:

/* Casio QV 2x00/3x00/4000/8000 digital still cameras are not conformant
  * to the USB storage specification in two ways:
  * - They tell us they are using transport protocol CBI. In reality they
  *   are using transport protocol CB.
  * - They don't like the INQUIRY command. So we must handle this command
  *   of the SCSI layer ourselves.
  */

umass.c gives the impression that CB is not supported (but seeing I don't
know the difference, I could be misinterpreting...).

I can't see any obvious NetBSD quirks which correspond to these issues.

-- 
Stephen