Never said it would - but if you are happily filling in other fields it would. I only knocked it together quickly, no error checking etc, but if you wanted to do that, just addBut it still doesn't let you enter a new row with just a press of the down arrow key as the OP said.
Field1 = Field1.DefaultValue
to the form current event
good find on the 2003/2007 differences by the way.