Hmm, does it print correctly if you do the whole book? If so I suspect that the 'final SFM' has ended up broken somehow.
As the ptxprint authors are not administrators of this site, it's hard to send you an email. See PM.
The best way to send a large file is via to share it via google drive, that way it doesn't clog everyone's email quota.
But... Have you got the very latest version of ptxprint? That's normally a good thing to check, in case the odd behaviour has been corrected already.