Distorted fonts when using a converted texturepack on startup

When I start the game with a resourcepack that got created from converting a texturepack with TextureEnder (lol), the font everywhere in the game looks like in "screenshot-1". However when I start with the default resourcepack, everything's normal.

Changing the pack on runtime doesn't change anything.

How to reproduce:
1. Take a texturepack.
2. Convert it using TextureEnder (from Mojang blog post for 13w24a)
3. Move the converted resourcepack to the resourcepack directory in /.minecraft/
4. Start the game
5. Select the resourcepack
6. Restart the game
7. Start eating hotdogs because of frustration.

PS: This may only happen if that texturepack has a custom font