Offline Lag

Game saves work perfectly fine when initiated (created), however, upon exploration and development of the world, blocks become unresponsive and reappear as though I was playing on a bad online connection.
When blocks can be broken and produce their miniature duplicates, the miniatures are non responsive and remain, uncollected and spinning, on the floor where they land.

I have changed all video and display settings to minimal, or off, yet the save still has the same problems.

When the saves do load, nothing is rendered, and 'Steve' is dropped into an empty world where he continuously falls. While falling, 'Steve' still has the ability to walk. (No falling animation)

Upon leaving, (Save and Quit), the world does not save and when re-loaded, 'Steve' is respawned at the original point.
(The sun/time is moved to it's last working position every time)