Ok submitting question here too in case someone else knows.

Im following the tut bren linked up a bit in this thread.  I get to steps 4 and 5 where basically I have created an edge on a cube around the middle.  Then I have used extrude to pull down for the length of the legs.  Then I am suppose to delete the top face of the cube and the bottom faces of the legs.  Thats where my problem happens.

(I deleted my original and restarted to see if problem recreated so you will notice no symatry (sic) in this.

When I delete the top faces I lose the whole portion that extruded and out pops this flat plane behind my pants.

First pic is me selecting a top face, second pic is after I hit delete.

I am:  aka Velocity3d