Angarvunde glitch?

[jasper1949]

I have done almost all of Skyrim. This is the only section I have not been able to complete. I have gone all through the tunnels and caves, killed all the enemies, pulled all the levers. I get to the final gate where Medresi Dran is running into a still closed gate. I even kill her to see if that opens the gate. No matter what I do that gate to the final word wall will not open. Is this a glitch in the game or have I missed something. I first did this a long time ago so cannot go back and begin again.