Side panels zoom animation

When changing the position of the center panel occur side panels zoom-animation
![ios simulator screen shot jun 11 2013 15 51 26](https://f.cloud.github.com/assets/124523/636920/ac170f4a-d295-11e2-9b67-d48a8cce3fff.png)
![ios simulator screen shot jun 11 2013 15 51 28](https://f.cloud.github.com/assets/124523/636921/b155c456-d295-11e2-8df7-9b2f0afa0490.png)
![ios simulator screen shot jun 11 2013 15 51 31](https://f.cloud.github.com/assets/124523/636925/c1188d56-d295-11e2-8802-0dab85667302.png)