Q: Why does the unregistered notice still appear in the metadata
panels after entering the registration code?
A: The unregistered notice remains present until
Lightroom is restarted or the plugin is reloaded using the Plug-in Manager
dialog. Once you have entered the registration code and taken either of these
actions the unregistered notice will disappear.
Q: Why aren't the GPS fields editable?
A: The fields available in panels are defined by
Adobe's Lightroom team and don't currently include editable GPS fields.
If you wish to edit your GPS data I recommend either using Lightroom 4, which
introduces a new Map module for managing GPS data, or use
Jeffrey Friedl's GPS-Support Geoencoding Plugin for
Lightroom which adds a number of features for working with and editing GPS
data in images.