It seems there are two types of memory sticks. The one type will be visible as /dev/umass0t?? the other type as /dev/
hd1t6 (example). As I understand a flash drive is mounted as /dev/hd? and then its partitions.

If a memory stick is inserted and the device /dev/umass0 is created, the memory stick will automatically be mounted 
under /fs/usb0, no problem.

If a memory stick(a flash drive)  is inserted and the device /dev/hd1t6, as an example, is created, the memory stick is 
not automatically mounted.

If however QNX boot up with the flash drive inserted (/dev/hd1), then the memory stick is mounted as /fs/hd1xxxx. If the
 memory stick is now removed and inserted, then the memory stick mounts automatically.

We have to write software to handle all this because the customer will arrive with any type of USB memory stick and I 
want the system to respond in a consistent manner.

To add to the confusion, it seems the way the device is created depends on the motherboard and the BIOS. On one 
motherboard, the memory stick is mounted as /dev/hd1 and on another motherboard as /dev/umass0.

Any information to understand the issues involved will be appreciated.