I am having so much trouble with the Paypal Express Checkout module. I have set international shipping values in both Paypal Shipping Calculations and in the Shipping Module that came with oscommerce, but my international buyers are never presented with an option to enter their address and they are not charged any shipping! I offer free domestic US shipping, but I need to collect international shipping charges and have quite a few international buyers, so this is a big issue for my shop.
I currently have oscommerce 2.3.3 right now and from reading the posts above, it seems that this issue was resolved for some people with v126.96.36.199. In hopes of addressing this problem, I have downloaded the upgrade files (I am running mac osx 10.9.2), but I am not sure how to install this upgrade with my current version. There is a catalog folder containing admin and includes folders, but it's been so long since I originally installed oscommerce, I am unsure how to go about uploading these files to the right spot so that they upgrade my version without messing up my current content...help!