This is what your model should look like starting step 36.

This is the flap you need to fold up. Crease this thoroughly, this is THE crease that matters for the sink.

The whole point about the circled area on the diagram and step 38 is that the section here does NOT need to be sunk, it needs to be held closed. I'm holding the area in the first picture; the second two pictures show how it'll look like once the section is already sunk.



Once that's all sunk, your model should look like this.

Hopefully this helps you out. If you need bigger/better pictures, let me know, I'll see what I can do.
-oz
