I believe that I have resolved my problem.
The problem was related to mapping the geolocation data embedded in the images.
While using my older Resourcespace version I had modified the config.php file such that only Google maps would be available in the Location Data section of the Resource view:
$geo_layers="gmap, gsat, gphy";
Since the svn update that I made included revision 8445, the Google Maps layer was disabled by default.
When I activated it using $use_google_maps = true; my problem disappeared.
I could view the gmap, gsat, gphy layers and the osm layer if added to the geo_layers configuration.
If I set $use_google_maps = false then the problem I was seeing reappears unless I also remove the google maps layers from the $geo_layers setting.
$geo_layers="osm, gmap, gsat, gphy"; => leads to error
$geo_layers="osm"; => works fine
My config.php file now includes the following and works fine:
$disable_geocoding = false;
$use_google_maps = true;
$geo_layers="gmap, gsat, gphy, osm";
Doug