Potty Training Cocker Spaniels

Question
I cannot seem to train my cocker spaniel to go the bathroom outside when I am gone - she is 7 months old and realizes that what she is doing is wrong (when I walk in a room where she has gone potty - she immediately hides under the table before I even say anything).  We have a dog door for her to come in and out to relieve herself and we also have another dog that uses this door and never goes potty inside the house.

What am i doing wrong?

Answer
Will she readily use the door?  Perhaps working to make her more comfortable with the door might help.  

In general, it is difficult to train a dog to do what you want when you aren't around.  Just providing better leadership might help.  The dogs see all the
people and dogs in the household as a pack with each having their own rank in
the pack and a top dog.  Life is much easier if the 2 legged pack members
outrank the 4 legged ones.  You can learn to play the role of top dog by
reading some books or going to a good obedience class. A good obedience class
or book is about you being top dog, not about rewarding standard commands with
a treat. Start at http://www.dogsbestfriend.com/