Dynamically adding a Cell to a TableView

I have a TableView that I build manually and display in a ContentPage. Later, after some user interaction I need to add a new cell to the Table. I am iterating through the table to find the right section, then creating a new TextCell and adding it to the section. I can verify in the debugger that there is a new cell in the Table.

However, the Table is not refreshing to show the new cell. Should this work? Is there anything additional I should do to update the table?

I've only tested this on iOS 7.