I noted this in or die and tutorials. Basically the isbn tag should take you right to the actual product page. But since the B&N take over of fatbrain, it appears the isbn links redirect you to B&N and whatever they're doing to redirect is foobar'ed and just leaving you at B&N front door. Check out ISBN 1565922204 which should take you to Advanced Perl Programming page in B&N's catalog but doesn't.

-derby