Adding a 2nd mine type to minesweeper

Hello, I'm a complete beginner with AS3 so I'm trying to start with something fairly simple (I hope!)

I've followed this tutorial for making minesweeper and want to add a second mine type. I'm unable to get both mine types to display in the game grid though. I have duplicated each instance of Mined and Mines to TestMined and Test to try and add this second mine, as well as adding a 7th frame with a bright yellow box to display it. To no avail.

Any help would be massively appreciated, here's a screenchot showing the issue and what I'm trying to do: http://i.imgur.com/Cd26n.jpg