Digital BW, The Print

This might be a tad of topic but someone here may have the 
answer. I am scanning 2 1/4 with my epson 1600 using 
Silverfast Scan software. Silverfast gives great control over 
scanning chromes, and b/w, as long as I don't scan HiBit. But I'll 
be darned if I can get a good scan in HiBit from Silverfast. The 
scans are dark and difficult to adjust in PS. Yet scans from the 
Epson driver in HiBit (even with the crude controls) turn out much 
better. So much better that I must be doing something wrong but 
can't figure it out. Any ideas? 

Dave