Hi Arie, can you please zip up and attach the .3dm model file for your circle and wedge that don't work?

That will help determine the problem you're running into.

If your extruded wedge is not a closed solid and does not fully divide the circle into 2 pieces then that can prevent booleans from working right. It is kind of easier to just use polylines or planar curves for these kind of cuts, MoI does some work to make sure that an automatic extrusion happens which goes all the way through the object.

But it is difficult to determine what problem you might be running into without seeing your model file.

- Michael