UPS Plugin Error: 110308 unsupported country code

I am receiving this error:

Error while sending XML to UPS. Error code: 110308. Message: Invalid or unsupported origin country code

Where do I set the country code? I have added and deleted zones here and there, but I am stuck...

Thanks,
Stef

Each zone has a 2 and a 3 letters code. If you delete and recreate a zone without setting these, HikaShop won't be able to send them to UPS and you will have that error.
You should make sure that all the zones you added under the menu System->Zones have the correct 2 and 3 letter codes.