I've reduced the margin-bottom on all checkbox and radio elements now, so this rule is redundant. As it was, when there was an error, all checkbox/radio bottom margins were reduced, so it was uneven, like this:

![screen shot 2014-03-28 at 14 16 58](https://cloud.githubusercontent.com/assets/2759279/2550513/fc14a6c4-b683-11e3-8795-fda9029a6d1f.png)