It was indeed my api access credentials. It worked first time through after I got those right. I sure am glad you can issue refunds for 60 days!
So, Im not quite clear about switching from sandbox to live testing... do i need to have both api access certs in the wpp_cert directory or do I switch them out? I guess i could leave them both in and just point the module to the correct one depending on live/sandbox.
Thanks again for your time/code. Nice work.
-bh