64 gig card showing up as 16Gig

Hi all,
I just picked up an hvx200p that came with a 64 gig p2 card. In 1080/24 mode it only gives me 16 minutes of recording time, which I think means it's recognizing the card as a 16 gig. I first thought it was a firmware issue but it shows it's running 4.06-00-0.00 which I believe to be the most recent. Is there a high capacity card option that I have to toggle? Is the firmware old? Should I re-load the firware? Is this model not capable of that size of card? Sorry for the noob questions, I'm quite new to this camera.

Thanks!
Tom