A local grass strip, ESGS, is selectable in the airports list, but a recent update had it disappear from the GPS database. Was that an intentional change reflecting some unknown-to-me change in the field's status, or did it just drop out accidentally when the GPS system was overhauled in preparation for the new G1000?
UPDATE: The ICAO magically started resolving after I flew in another part of the world, so the symptom obviously was local to my machine. I'm still interested in the cause, but I no longer experience this specific problem.