When I delete objects VB.Net is not always cleaning up after itself

Why does VB.Net keep references to objects within its "designer
generated code" and xxxxxx.resx files even after the objects have been
deleted from the project and the solution rebuilt.

For example: Code referring to dataset names still remain in the
"designer generated code" and in the Form.resx file even after I
rebuild the project.

This causes a problem. When I try to re-create the object it will not
let me name it as I like. It says an object already exists with that
name.

Then I have to try to find and delete all the references to the
obsolete object so that I can go back to coding.

What is the story behind this? Is there a way around it? Is there a
way to clean it up? What am I doing wrong?