Couple questions for the frequent Emirates travelers...

I'm flying to Shanghai from JFK via Dubai in J class with a 6+ hour layover. Will I be able to check my luggage all the way through from JFK so I don't need to recheck it again in Dubai? Please note because I used a voucher issued by Emirates for the JFK-DXB leg (due to some issues during my last trip), therefore the two reservations were made separately. I called the Emirates office in NYC and they didn't give a definitive answer. I have quite a lot of luggage this time so it would be a pain to have to claim it in Dubai, go through customs and recheck in again.

Thanks!