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.
That is great to hear that you got it worked out, if you would please post back with what action you took to resolve the problem so that others may benefit from your experience. 


