How to reverse geocode in LR4 if image is already tagged with latitude/longitude

I tried again now with my main catalog, but it still does not work :-( 

I tried yesterday to migrate an old test-catalog from LR 3 to LR 4 and all photos that already had GPS info (both iPhone-phoots already tagged from phone and photos tagged with an external program) did get the location fields filled in. Though grey, but it does not matter, because when I use the library filter to browse the locations, it used the location names automatically retrieved by the reverse geotagging.

So basically: I did nothing. It just worked. When I put an image on the map it also got the location fields.

However when I tried this on my main library (also converted from LR 3) the day before it did not work. Will try that again in case the whole problem was due to some glitch between LR and Google.

This has to be a bug.  The only way to write the location information to xmp is to click on each field label one at a time.  This has to be done whether the GPS data is entered by placing the image on the map from Lightroom or getting the GPS data from a tracklog.

What's more, if the image is opened in Photoshop (from Lightroom) the location data is missing unless it has been saved as above (ie one field at a time).  So right now the location data is absolutely useless.

Fortunately Jeffrey Friedl comes to the rescue!!  The reverse geo-encoding (Reverse Geo tab) works perfectly once the photo has the gps coordinates (which can be put in through the jFriedl plugin or from Lightroom - or any other way).

What works quite well is to load the tracklog and Auto-tag the images - and then just run the jFriedl Reverse Geo to get the location data (which is more complete than what LR gets anyway).

Ah. Thanks.   Now I understand that clicking on each individual field label will commit the value filled in by the reverse geocoding.  (I misunderstood earlier and thought there was some sort of "commit" button in the LR interface.) 

Sadly, it appears that there is still no answer to my original question as to whether it is possible to have Lightroom do the reverse geocoding lookup using the lat/long. already present in the file.  I don't want to dump this data and then try to individually drag the images to the map.  If LR can't do this, perhaps there is some other geocoding software which can do it outside of Lightroom.

Posted in the LR4 forum is the idea below:

Uncheck the reverse geocoding checkboxes in the catalog settings.

Restart LR.

Enable the checkboxes.

Now it works.

Well, it has worked for the person that posted that, and for myself.

If any of the location fields have any data in them, LR will not get the location data.  You could check to see if there is anything in there: even a space will stop the reverse geocode. 

It's pretty stupid cause say you reverse geocode, then you put in the Sublocation manually, then you move the image on the map - all location information gone.  Move the image pointer back to it's original location - no location data (except for your manually entered sublocation, of course).  Makes you wonder who tests these programs.

Same question here.  If I go to a image that has the latitude and longitude already in the GPS coordinates, Lightroom 4 will not allow me to Auto-Tag Photos to reverse geocode the images with the City, State, Country.  The Auto-Tag Photos menu is greyed out.