Comment 6 for bug 191316

Still not fixed with 8.10rc with today's updates.

With updated Nikon firmware 1.11 and camera set to PTP/MTP. (see screenshot-1)

When the camera is mounted in Mass Storage mode, F-spot is not automatically launched, but when it is started by either window (see next comment), it is able to import the pictures without unmounting.

So I think it has something to do with the implementation of the MTP/PTP Nikon window locking the USB-port.
The Mass-storage window does not lock that port, or F-spot does not require a lock or can accept a used port with a lock by another program