Texture packs screwing up

hey guys...every texture pack I use above 16x16 screws up... in the picture below (in the spoiler)...it's only the 3D part... i like the texture pack I use and i've tried many of them... but they all look like this.


Look at the Red Arrow in the bottom right corner, it's pointing to the messed up part...it's a 64x64 texture pack, and the part it's pointing to is like 16x16