Although iOS7 has encouraged less chrome in our user interfaces, some of us still find background views on table cells relevant. A bug in iOS7 (present at the time this post was written) inadvertently covers up the stock Delete button on a table cell if you have a backgroundView set on the table cell.
Initially, you see the Delete button and then the backgroundView slides over to the right to completely cover it!
Many have reported this problem, such as this example from stackoverflow.com.