Fix checkbox label wrapping issue

Before:
![screenshot 2014-03-24 10 07 00](https://f.cloud.github.com/assets/870979/2501684/d7218de0-b36e-11e3-9beb-3bbc864115ab.png)

After:
![screenshot 2014-03-24 10 07 08](https://f.cloud.github.com/assets/870979/2501683/d7218570-b36e-11e3-9f38-c3691a017b0e.png)