Hello mmcash and all the others with non-matching amount of the found trackables. You can verify on the Geocaching Trackable search page by filling your username
that the geocaching will also list the same number as project-gc. This is caused by some double-logged trackable (as we have simillar problem with caches) and for some reason, the amount of logs instead of amount of unique trackables is displayed on the geocaching profile page.
There are cases, where finding and logging single trackable twice makes sense (you can cross its way more times), but this is usually caused by the group-logging.
So this is not a bug in PGC, but in Geocaching, which does not list trackables, but logs! If this is an issue for you, please open a bug report on Geocaching, who does it wrong and very confusingly.