A bit verbosely, sorry. My way of organizing photos is in folders photos/year/month/day. So I had photos/2015/January/ and then 2001, 2101, 2201, 2301 (DDMM)I got the photos from my DSLR and a few from my Casio pocket camera and put them in the four folders. Then I made Panorama photos with ICE.
I opened a day in Geosetter and then the appropriate .log data from my sony GPS. There were a bunch of photos from the plane which I sychronised manualy with the flight data history from www.flightradar24.com. In this way I did with all 4 days. after that I straightened, cropped, optimized partly with Picasa, partly with lightroom.
Then I started uploading to Panoramio, day by day. All geodata were shown in PA, so all photos were mapped. The auto tag gave the appropriate tags on 2001 uploaded 3101 , 2101 uploaded 0102 and 2301 uploaded 0302 . Only the photos from 2201 uploaded 0202 showed the year as a tag.
So basically I had all photos done the same way, all photos received geodata the same way, only on the 2nd of February uploading gave the tag problem.