Just a word of advise, when using a module that is not working as advertised, I always assume that the version of the module that I am using is broken. I then go to CPAN and get a couple of the most recent versions and try them. More often than not, there is a small mistake in the version that I am using.

Let's say you are currently using the most recent version of PDF::API2 (If not, try that first). Maybe the author corrected a problem from the previous version, but never tested the fix on a multiple page document. Perhaps the previous version does everything you need it to, and it works on multple pages. Now, not only do you have a working version, but you have helped the author test. You should let them know what your problems/fix was so that they can fix the problem.

Though it can be a waste of time, this has helped me (and module authors) more than once.