Sorry to hear that geotagging isn't working consistently (and that no one responded before your vacation). If some photos are geotagged, that usually indicates that the card and software are working correctly. In order to geotag your photos, the Eye-Fi card needs to be powered on long enough to find multiple wi-fi networks in range, and a few of these must be indexed in Google's location database in order for Google to return a location to us.
This is nature of WPS, and sometimes the results are inconsistent. It depends where you are, how well the card is able to find nearby networks, and whether those networks are found in Google's database. For more information: http://support.eye.fi/software/problem/ ... eotagging/
I hope this is somewhat helpful...