I finally figured out what my problem is. I had to completely reinstall OSC, install WPP (worked fine) and then install modules one at a time until I found what broke it.
The culprit?
Search Engine Friendly URL v1.13_1
http://www.oscommerce.com/community/contri...Engine+Friendly
I install this module and immediately WPP stops working. I can't figure out why but basically the payment process appears, to the customer, to go right through. But it never hits paypal. It doesn't even return any errors or anything.
Anyway, I guess I'll just "uninstall" SEF since being able to accept payment is somewhat critical but it's really a bummer that it breaks WPP.
Does anyone know a good SEO url alternative? I would like to have my urls look like this (spaces added to prevent linking):
http:// www.domain.com / category / subcategory / product-name-here /
Thanks!