set focus problem

Why does this field turn black when I first pull up the form? It is the field that I have set focus for the user to begin at this field. Sometimes when you start the field is white and you can see the cursor and the typing and everything is fine. Other times you start and the field shows black and the cursor white and you can't see any typing until you leave the field. Help!

This is what I have now:

this.getField("NAME").setFocus();