The right side of the screen does not render well

What I expected to happen was...:
See the all game screen rendering well (I know, it is not a great description).

What actually happened was...:
I start the game, in a existent world and in window mode, then in the right side of screen I saw a band when the textures looked faded.

Steps to Reproduce:
1.- Open launcher
2.- Start game in 14w08a version.
3.- Keep the video options in windowed mode.
4.- Load a world (in this case it is another hard disk with NTFS format).

I tired to reproduce it, but never happens again.