camera problem

Hi everyone, I'm working on a 3D globe on Android, and it works great except for a camera problem I haven't been able to figure out yet. I'm rotating the camera around the globe in a timer:

double time = (System.currentTimeMillis() & 0x0000ffff) / 1000.0;

camera.eye = new Vector3D(Math.sin(time), Math.cos(time), 0);

I expect the camera to orbit at a constant distance from the globe. Instead, it seems to wobble back and forth a bit. Also, there's some clipping that comes in and out on either side of the globe as it rotates. Check this video:

http://www.filedropper.com/globe

I'm hoping that someone has seen this kind of newbie mistake before and can give me some idea where my problem is. Any ideas?