Oddly enough I came looking to the Axiom message board tonight with the same problem. I bought a bunch of spades from Parts Express (http://www.partsexpress.com/pe/showdetl.cfm?&DID=7) and they don't fit. I'm going to call them tomorrow to see what gives, but the bottom line is they won't ever fit and I have to send them back.
I've otherwise been very happy with what I've ordered so far from Parts Express, but this item needs a footnote to alert the user that it won't fit a standard 5-way binding post.
I guess the price was too good to be true...
