I had that happening to me.  It might not be the same situation but here it is.  

I would zoom the camera in and parts of my model I was focused on would disappear.

I switched to a top view and found because of my mm on my camera, the camera was really close to the object.  It was actually when I 'zoomed' in it moved the camera into the 3d object which when the multi-view it just showed parts of the 3d object vanishing.  I thought I was going crazy. 

What I ended up doing was moving the object further back  and chaning the mm on the camera to something better for the shot and I could zoom and move around so much better.  My camera was so close that even little pans of the camera ended up making the objects appear that they jumped around even though I just wanted a hair adjustment so to speak. 

Whats odd is I went to original file and tried to duplicate it and if I set the camera mm back to something unreasonable and scaled you can see that the camera is too close, parts aren't vanishing etc.  Perhaps it was a glitch and when I clicked on a MM for the camera setting it 'fixed' itself.  I am not sure, but you could give it a try and see if it 'rights' itself.  I will have to recreate the scene from scratch and see if I can get it to duplicate it now.  I think it had to do with something about small model to camera size or something.  If I can replicate I will post again