Correction: I have just noticed that all of my hopper minecarts are gone. I had one running a sheep shearing farm, and the other running a honeycomb farm. Both disappeared upon my signing into the ream this morning.
Oh, I forgot to mention. Accompanied with this is a case of hostile mobs spawning inside my very well lit homes. So far, we've had 2 instances, one where a skeleton spawned in a fully lit stairway, and the other where a zombie spawned inside my castle where my iron golem despawned. I'm not sure if this is connected; however I felt it may be important.
This is the mapped area. Before the bug was encountered, this whole area was ice. It appears to be encroaching on my builds in the region.