After getting a Panasonic Lumix DMC-FS6 as christmas present for myself last year i today took my first try at photo mapping with Josm ... and failed.
Camera and GPS device clocks seemed to be almost perfectly in sync but i could not convince JOSM to load those issues and associate them with the loaded GPX track at all, no matter what i tried.
After double checking the photos EXIF tag entries and file system time stamps and the .gpx file entries for quite a while i finally found the reason:
The camera still believed to be living in 2009, it hat somehow forgotten to change over to 2010. The original test photos i did last year clearly show that i had set the date right, so i'm afraid i now need to remember to double check the cameras date every new year now ... :/