This happened previously with another world I started in 1.7.4 and it also crashed and is missing a chunk which glitches the player. The program stops responding, crashes, then when the world opens back up it's missing entire chunks. The chunks are from sky to the abyss. It can't be crossed or entered without causing the player to slowly sink shakily through the hole dying slowly.
http://i859.photobucket.com/albums/ab153/MahoHaku/Minecraftglitch_zps823cdbf6.png
Image link of missing chunk in previously crashed world.
I partially feel it's a combination of being on so long, maybe I maxed out memory and cache on my computer... but I also feel a huge thing that causes these crashes most often is being over 3000 blocks from spawn point. Which never happened to me before I went from 1.6.2 to 1.7.4. Also only happens only when in multiplayer or LAN.

What I expected to happen was...:
If I left the game alone and shut down all other programs it would start responding again

What actually happened was...:
the world crashed. I'm not sure if the world is intact. I am going to check it.

Steps to Reproduce:
1. Open a world and set it to lan for multiplayer use on version 1.7.4
2. Everyone has render distance at 10 chunks. Mostly play 3 player.
3. play for 2 hours or so... traveling/exploring mostly and after we get about 5000-6000 blocks from the origin point of the world and from each player it begins to glitch then crash.