Hmm - I'm looking at my lvl 2 trader so that is what it is - my general tab says Jewel Craft Mastery - My Achievements - Tradeskills from the EQ button says Jewelcrafting - I see the only difference as 1 word or 2.
The same type of thing happens with "Blacksmithing" and "Smithing". Dr. Strangelove, I've stopped worrying about it (or caring. And as someone with OCD, that says something. What really grinds my gears is inconsistency with zone names. Now, that's something that actually bothers me.