Billing and shipping mismatch on some orders
Afghanistan is the default country in country select lists since it's first alphabetically. It appears to me that perhaps some part of your checkout form is causing a previously saved address to be overwritten. This is an infrequent but common issue when combining a variety of Ajax related features on a single checkout form. I'd begin debugging there to see if you can isolate the point at which stale address data is saved to the active billing profile accidentally.