[1.8] Item textures broken in hand and item frames when switching from 128x to 64x texture pack

Partner Rank: 2 

Partner Team Reporting: Jamizzle

Summary: Item textures broken in hand and item frames when switching from 128x to 64x texture pack

Verification builds: beta 1.8.0.8

When loading up a world with an HD texture pack at 128x resolution everything appears fine. Editing the same world to use a 64x resolution causes many item textures to glitch when held in hand, as well as when placed in item frames. 

Impact: Makes resource packs at 64x unusable due to items in-hand being unreadable.

Repro Steps:
1. Load up a pre-existing map, or a newly created map and assign a 128x resolution texture pack
2. Place item frame
3. Put oak door in frame
4. Save and quit
5. change settings of map to use 64x resolution

Observed Results:
The oak door in hand becomes glitched and enlarged. The same oak door in item frame becomes glitched enlarged and no longer centered in the frame.

Expected Results:
Should be able to load a 64x version of a texture pack and have item textures appear normally. 

Screenshots/Videos attached: Yes/No
yes

Regression Builds:

Uncertain, but pre 1.8 

Notes:
Seemed to be happening with both my premade map (made before 1.8) as well as a freshly created map. Occurs using Chroma Hills/ Sphax and ZigZag from what I can see.