Problem with extruding :(
I'm doing a tutorial from Maya 4.5 fundamentals, where I am box modeling an alien with a cube and smooth proxy. Everything works great until I try to extrude the front of the face. In the video tutorial, the guy selects two front faces and extrudes them, and their is no gap between the two faces (but there is a gap between the extruded shape and the mirrored image.) Then, he deletes the faces between the extruded shape and the mirror, and it all joins together. Well, when I do it, it makes kind of a hole in the front of the shape. I have retryed twice. I figure there is some kind of problem since when I extrude the faces it turns to four instead of two. Anyone have any idea what is going wrong? Thanks.