Parent the lid to the base.

Open the Hierarchy window.

Select the base.

Click the Create Figure button.

When prompted type in a name for the figure.

Click OK, it will then get saved to your primary Poser content library in a figure folder named New Figures.

Clear the scene.

Find the New Figures library folder and load the new figure.

Select the base and in its properties uncheck the "Bend" option.

Repeat for the lid.

Select the lid, open the joint editor and reposition the green axis to be at the hinge.

Set bending limits as before.

Hope that helps.