New gaming rig can't run Minecraft maxxed?

So... I bought a new gaming rig - including an i5-3570k and a GTX 670.

To commemorate this, a friend bought me minecraft. (He'd been trying to get me to play for a LONG time.)

Now, this rig is able to run basically everything maxxed out at 1080p... except for minecraft.


When I try to turn up the draw distance, I get HUGE holes in the terrain, that only go away when I stand on them...
It's not that it's struggling to render a lot of objects - I can see the blocks on the other side of the hole, and I can see even further to the bottom of the terrain through the hole, but other than that, inside it it's just the blue background.



So what am I doing wrong?

I've got all the latest drivers, and I'm pretty sure I've downloaded the 64 bit version of java and correctly followed online instructions to make a shortcut that runs it in 64 bit.