Well, like I said in a previous thread - (I had two problems, payment process wasn't working and shipment costs weren't being added, but they were related and the same problem).
I am using UPS shipping, and the Access Key I got From UPS was for their HTML process, not their XML process, which is apparently what you need for Powerstore. So once I switched the html access key to an xml access key (its just a different number) in the globals file, everything worked out fine.

