I'm sorry. I'm not sure why that happened. I can see why you would get two, because the order was placed in two batches.
Paypal wasn't designed for handling a complete order-entry system. I considered subscribing to other services that work on top of paypal, but they too have significant limitations, and some of them are rather expensive on top of it. Typically you pay not for a complete turn-key system, but for having it dumbed down enough for non-technical merchants to handle it. A really complete off-the-shelf solution might involve hiring consultants to do some custom javascript programming and implementing their own code to do stuff like look up sales tax for local sales, which are down to zip + 4 granularity. Two people who live in the same zip code don't necessarily pay the same sales tax, due to it being applied at at least 3 different jurisdictional levels (state, county, city), plus we have "special revenue districts".

Other people have systems that work better, and my guess is that to a certain degree, it was luck finding someone to handle the merchant systems right the first time.
Now that the system is up-and-running, we have enough momentum to have a chance at working on process improvement.
