Block sounds are distorted if walking with left and right keys

Sound chops up when you are walking left to right. Only affects 14w06.

Reproduction:
1. Start up 14w06b/a
2. Open a world
3. Walk with the right and left keys. The sound of whatever block you are walking on will be distorted.

Just for notice, I included a short video too in the attachments.

[EDIT: Only works for "soft blocks", which creates sand/grass sounds when being walked on.]

[EDIT: It actually works for most blocks, it's hard to hear the sound chopping on other blocks "eg. stone" sometimes.]