Digital BW, The Print

I've searched through untold numbers of Yahoo groups to find one 
that addressed problems I am having with my scanner.  Can't find one 
and this group appears to have the most erudite membership of any 
I've seen.  So--- having to do with B&W negative scanning (color 
negatives too)--- after 11/2 years of using this Epson 2450 the I am 
being presented with very narrow or out of alignment thumbnails and 
scans.  Yes, I've spent the $ to talk to Epson.  The tech read me 
the same materials I'd already gone through online and the final 
input was " sometimes the driver just does this."  I've reloaded the 
software 3 times.  Spent hours trying to finely tune the negs in the 
holder for precise position and all to no avail.  I can scan the 
same group of negatives several times and get several differnt out-
of-alignment thumbnails.  The scanner hasn't been moved or roughed 
up, everything elso works perfectly, transparencies, MF and flatbed 
all scan without a problem.  Anyone had a similar problem?  Any help 
out there.  I was making some progress with my B&W printing when 
this problem slammed me.  Thanks.

Barbara Woolner