Zones for dummies?

I'm setting up my first Zen Cart store and I'm having trouble getting my head around how Zen Cart uses zones and zone definitions in its (and add-on) payment and shipping modules.

I've gone into the Countries set-up and deleted all but the countries I intend to do business with, then went into Zones and added them there also. I also added Philippines as a zone definition. I want to add Metro Cebu as a subzone under Philippines for use by the Store Pickup shipping module but when I try to add it the Country pick list is empty (there are no choices to pick from) and the Zone pick list only contain All Zones.

What I'd like to do is offer PayPal to everybody, only offer direct bank deposit to people in the Philippines, and only offer store pickup to those customers who enter Cebu City, Mandaue City, Consolacion and Talisay City in their addresses rather than have it be available to everyone in the country. But I don't really understand how zones and zone definitions work in the first place. Help?

https://www.zen-cart.com/tutorials/index.php?article=69

Well, that vaguely explains zones and zone definitions in general, but I think I found the more detailed information I was looking for elsewhere.

It seems that Zones are equivalent to states, provinces, districts or what-have-you within a country. Zone Definitions are logical, custom groupings of Zones designed to help you configure tax rates, shipping and payment modules.

Let's say you do business entirely within the USA only. You want to charge flat-rate shipping according to what part of the US your customer is located in: West Coast, New England, Southwest, Midwest, etc. You would add a Zone for every US state then add a Zone Configuration for each shipping region. Is that correct?

What I don't get is how Zen Cart knows which Zone Configuration applies to a given customer. I suspect it's supposed to get that from the Sub Zones you add inside each Zone Configuration (going by the customer's state in the example), but my Zen Cart won't let me add any Sub Zone except "All Zones" with no country. The Country pick list is empty as is the Zone pick list. In the above example I would add a Sub Zone for ever state within a given shipping region with the US as the country. But I can't! This is starting to drive me crazy! (Luckily that's a short drive. :P)

I solved it. The problem was that importing the Philippines zones from the file I got in the free add-ons section zorched my database and broke zone definition subzones. I did a clean reinstall of Zen Cart (1.3.9f) and manually entered all the zones I'll need. I guess the moral is: be careful of doing direct database importations to "save time". The more haste, the less speed.

Next time I set up a Zen Cart store, if I ever do so again, the first thing I'll do is set up countries and zones, by hand. Then I'll configure the store, then the categories, add some test products, configure and test payment and shipping modules, then do the theme last. That's the way I'll (re)do my store now.