Please don't take offense to my post as I may be a little blunt here.
It is common knowledge that cutting chipboard with any type of die cutting system will be tricky. If you have the expectation that each and every die should cut cleanly each and every time then you are setting yourself up for some disappointment.
Yes, you are right in that they should work BUT as everyone will tell you die cutting is not a science and the success rate is NOT 100%. I am sorry to have to break the news to you but it is the nature of the beast.
PS but if you really think your one die is "not quite right" then return it. Sometimes these things are defective.