zend_pdf can't read existing pdf

I'm using Zend_Pdf to generate PDF files, based on existin开发者_StackOverflowg PDF templates. The problem is, I can't read any of the templates - I get a "File is not a PDF." error because the first 4 characters in the file are "%???" instead of "%PDF" (I used "head" to check this).

Is this a character encoding problem? I believe the templates are in ISO-8859-1, must I set something in Zend_Pdf_Parser to handle this?

Thanks

---

to answer my own question, I moved to Perl PDF::Extract and it's working.