Help: My new JVC HU keeps shutting down

I just installed a new JVC HU in my truck last night and thought all was well. I'm getting sound on all speakers... I thought everything was good to go, but this morning when I drove it I found out if I turned it up too much (not a lot just enough to hear clearly over the rain) it would cut out and shut itself down. It was much more sensitive to this with AUX/USB and my Ipod. The radio seemed to handle a bit more volume before it began cutting in and out and shutting off for a second.

It seems to me it's almost like it's shorting out or something?

I grounded this thing to one of the bolts behind the HU.

My one thought is, because I didn't replace the speakers maybe they're shorting out? Or maybe the HU sees they can't handle it and shuts off?

I know the stockers run 2ohms or whatever but I was hoping to run them a month before I could dump some money into speakers...

Any ideas???? Please?

Here's the unit I installed:
JVC KW-XR610 CD receiver at Crutchfield.com