Digital BW, The Print

Do I have to do something special to get the program to see 
> both scanners?
> 
Yes, buy it again for the 2nd scanner :-( 

I may be wrong and someone else could correct me, but I think that 
each scanner has it's "own" Silverfast to drive it. Also check their 
website - there is tech support and a user forum 
http://www.silverfast.com/

They do also have SF HDR which is a standalone application that'll 
read 16 bit RAW files scanned on any scanner or from any digital 
camera. But that's not exactly what you're asking for.

Frank