Location Contextual Filter: Distance/Proximity works for all nodes but one Drupal 7 site with Location and Location CCK modules.

Client has custom content type with Location field provided by Location CCK module.

Each Location node has a Views block display of Nearby Locations with sort criteria “Location: Distance / Proximity (asc)” and this works for all nodes except a new one recently created.

In Views UI, if I preview with contextual filters, I see the closest four locations sorted by proximity.

But viewing the actual node, I see four other locations that are quite some distance farther away.

What could be causing this, and how should I troubleshoot it? (I have cleared the cache!)
I did not figure out why this is happening, but I was able to enter the latitude and longitude manually. This solves the problem for the short term, since the client does not add Location nodes often. I'm leaving the question open in case anyone has a clue!