I just did that part about a week ago. I didn't have a problem with it. I don't know what it could be.

Are you using the poles? Because you don't use the poles to reach the dagger. You only use one pole, and that's the one you use to go from the collapsing ledges to the main platform.

You run up the bottom of the statue with the R button, and then you go to the long shaft and just jump from the left to the right until you reach the top.