thundering1 was wondering,

get XP [snip] but I'm not sure you can buy it anymore

You could still get XP pro from DirectDeals http://directdeals.com/ for ~ $135
-- if you really wanted to do that.  LOL

OTOH, now that it has been superceded, I'll probably use my extra copy when
I build my next PC.  LOL

would a USB Hub work,

No. 

or is it a matter of ME

No ... it's a Windoze limitation -- only one scanner to a configuration.  My
guess is that someone was afraid that a PC would not be able to keep up
with the data flow from 2 scanners operating at the same time. 

If anyone has a better explanation, I would be delighted to hear it. 

colors [snip] tweaking [snip] most often you can save the Settings and
recall them

The software for the PrimeFilm doesn't seem to have that option. 

On a go forward basis, would a shot of a grey card per roll help? 

How would that work?  (procedure?)

Does it operate through Photoshop, possibly?

If the other scanner is not attached:  yes

If the other scanner is attached, Photoshop locks up ... three finger salute, etc. 

hope you still have hair left!

Oh yes ... here is an example ...

On the way to Bonnie Brae (June, 2001)
http://www.users.nac.net/mdiehl/kilt/BonnieBrae.htm

I admit, it's not a current picture; styling is now different; but you get the idea. 

--
Martin