Why am I missing textures while using the Shaders mod?

When I use the Sonic Ethers Unbelievable Shaders, players, some blocks and all held items are just a gray box.

EDIT: I'm talking about Minecraft, version 1.7.4, and use GSL Shaders mod

Guest

Are you sure that you're using the correct version of Minecraft? As in, the recommended or latest version for the shader?

Emerald