Lennart Augustsson writes:
> pipeh is not supposed to ever be NULL, so something is wrong in
> ugen, I guess.

It is entirely likely that Sierra Designs firmware in the Nikon 990
camera is taking quite a few liberties with the USB spec.  The Nikon
does such nice things are requiring a "clear halt" after every single
camera command.  I would not be surprised to hear that the Nikon is
also doing something to prevent pipeh from being set up correctly at
the time the ugen code expects it to be set up.

-wolfgang
-- 
Wolfgang Rupprecht    <wolfgang@wsrcc.com>     http://www.wsrcc.com/wolfgang/
Coming soon: GPS mapping tools for Open Systems. http://www.gnomad-mapping.com/