There's something strange going on there, it seems that you have got those edges set to SubD whilst the rest of the model isn't. With those edges selected, press '1' on your keyboard. Delete all history, and try to extrude those edges again.
I followed your advice but it still won't let me extrude
Okay, any chance you can upload your Maya file for me to take a look at please? http://www.mediafire.com/
Actually, the file shouldn't be too big. Attach it to an email.Jonstewartcg@gmail.com
Hi Nat,It seems as though you have quite a way to go to finish this. Come and see me if you are struggling to complete.