I don't know a d*mn thing about Canons, but the HP duplexer attachment
for some printers is like that. The software lets you choose whether
your pages are to be printed as if in a book (short edge for landscape),
or as if in a tablet (long edge in landscape). The software then
automagically orients the information going to the printer to accomplish
it. Assuming the Canons work the same way, if the OP means that his
Page B isn't oriented the way he wants it, I would blame his software,
not the printer.
TJ