i have talked to the stone golem three times i have talked to durlags ghost afterwards and i have searched the whole level completely about 50 times and still the door won't open next to islanne. what should i do.

You'll know you've done the lot when Durlag LEADS you up to the door near her. Where have you been from the stone golem? Did you make it to the throne room behind the secret door in the cave area which has acidic floors? That room is in the SE (bottom right) area of the green caves - it's actually on the east wall (right side of screen) and you have to cross acid to get to it. There's also another secret door in the SW srea (bottom left) on the south (bottom) wall. Re the throne room passages - have fun.