The shadow can break and repeat under specific conditions, not related to the resource pack (or .mcmeta files).
The issue seems to be related to the location of the item frame with the compass in it, and where you throw an item. It can be reproduce in a new world:

Steps to reproduce:

• Use default resource pack (or any other)
• Switch to fancy graphics (GL ERROR won't show up at fast graphics)
• make a new creative mode/superflat world or use the attached world MC-18752.zip
• do the command /tp @p 0 5 0
• middle click grass, place one
• get an item frame and compass from creative inventory
• place item frame then compass
• ## GL ERROR ## : @ Post render 1281: Invalid value will throw in the dev console
• while looking at it, throw something on the ground near it

Affects AMD Catalyst 13.12:

OpenGL: AMD Radeon HD 6700 Series GL version 4.3.12618 Compatibility Profile Context 13.251.0.0, ATI Technologies Inc.

Also affects nVidia GTS 450, NVIDIA Driver Version: 319.32, NV-CONTROL Version 1.29, GL version 4.3.0.

Minecraft / OpenGL / LWJGL gets messed up after that, the shadow effect will affect other worlds too until Minecraft gets restarted, or until resource system is reloaded (such as f3+t or changing resource packs).