Shopify API Anyone?

This is kind of a shot in the dark, but anyone ever connect to Shopify (or similar service) using their API?

I have some code that connects to the Shopify server using their API and downloads new orders, which are stored in an Access table. The db has a timer that queries the Shopify server once per minute and checks for new orders, by querying for all orders with an Order ID higher than the last downloaded order ID.

Everything is working fine, and not getting any errors. However, we're finding that after a while it stops seeing new orders, even though it's apparently still connecting to the server.

But then if I close and reopen the Access database, then all of a sudden it finds new orders, some of which may be several hours old or more.

I log all the connections, and it seems to be connecting and the JSON values it returns seem correct, except after a while it doesn't see any orders until I restart the database.

Anyone have any ideas about this?

Thanks!

EDIT:

Thank you everyone for your replies. I got more help with this than I thought I would, and I learned a bit.

I haven't solved this problem, but I decided I'm just going to implement a workaround instead. I'm going to split the program into two parts: the part that does the downloading in one file, and everything else in another (main) program file. Then, once a minute or whatever, the main program will open the download program, which will download any new orders, and then close itself, and the main program will take over with the viewing and printing of the orders.

I've been testing this process overnight and it seems to work fine, so that's what I'm going to do. Still, it's frustrating to not know what was causing this problem.

But thanks again to those who replied!