The answer to you question, while it may be unsastisfying, is "probably yes." The fact is, when the publisher failed to pay you (assuming that there actually was money due), they materially breached the agreement. Now, the "probably" part of my answer refers to the possiblity that they could sue you if you took the book elsewhere, and argue that in fact the nonpayment was a minor breach. Unfortunately, once it gets to court there are no guarantees. So what you may want to do is to send them a letter saying that you believe that they have breached the contract and that you have the right to pull out unless they send payment right away. Then see what they do.
Depending on the amount of money involved, it may be worth your while to seek an attorney's advice on the situation. I would be happy to speak with you, if you would like to call my office.
Answered on Mar 24th, 2013 at 2:02 AM