New Immigration changes effective February 15

All visa changes such as extensions, re-entry permits, etc. must be made at immigration offices which have jurisdiction of your area of residence.

Persons residing in Sakon Nakhon Province must use the immigration office in Nakhon Phanom. 

As an example, if you have a yearly visa and wish to travel outside Thailand,
you must apply for a multiple entry permit at the Nakhon Phanom immigration office prior to leaving the country.

For me, the yearly visa renewal which I accomplished in the past in one trip will now require three trips.

A round trip to Bangkok to visit the U.S. Embassy for a letter verifying my income.

A first trip to Nakhon Phanom to apply for a yearly extension.  

Since these applications are forwarded to Bangkok for approval, a second trip is required to complete this process.