G'day russellf,

Welcome to the monastery.

As you haven't provided any code, it's not possible to advise where the problem might be. Please read the guidelines in "How do I post a question effectively?" to find out how you can help us to help you.

I do note that page and corefont are PDF::API2 methods (not PDF::API2::Simple methods). PDF::API2::Simple is described as a "Simplistic wrapper for the excellent PDF::API2 modules": your problem may simply be how you're attempting to invoke those methods. You might also consider using PDF::API2 directly and bypassing any wrapper issues.