Summer of 2004 at SEA Had BP for a Frontier flight SEA-DEN leaving at 06h30 BP said SSSS but the screeners did not give me secondary at the checkpoint. When it was my turn to board the Gate Agent would not allow me to board and called for the TSA and after a considerable wait I was given the secondary near the gate. The screener asked me if I was military and where all I had been since I cleared the security checkpoint and then I was allowed to board.