spreadsheets

I am a lumber shipper for a large sawmill. I ship loads of
of lumber on flat rail cars. I wrote a program in excel that
allows me to layout all the loads so as they will fit
onto the flat car. My program calculates footage, weight,
and the flat car layout. The sheet works great, but
as with all things, we must tinker,. The problem now is
I have tried to add a formula to the sheet that calculates
the weight of the flat car based on the following
formula. This formula is part of a group that works well
on another sheet, but will not work on the main on.
Here it is ,=If(A1="FIR",1,0)*b1*175.This formula just
sits on the main sheet and does not respond to the
cell input. I have removed cell protection. Saved it under
another name (not template) . I am stomped , could anyone
help. Thank you , Bill