[SOLVED] Why do I get two QDockWidgets in Qt Designer when I only dragged one onto the form?

[codewriter]

First, let me state that I want to use Qt Designer to create my GUI.
I wish to create a Dock Widget that holds a List Widget.
There are my actions in order:
1- Drag Dock Widget onto form
2- Drag List Widget onto Dock Widget
3- Press F5 to invoke debug build
4- During runtime I see a window with TWO Dockwidgets with one List Widget in each

In the Qt Designer form I only see one Dock Widget with one List Widget
The Object Inspector shows:
dockWidget ..................................QDockWidget
......dockWidgetContents.............QWidget
...........listWidget...........................QListWidget

Why is this happening and how do I fix it so I get only one Dock Widget at runtime?

[codewriter]

Apparently, when I redid the whole GUI in Qt Designer my problem vanished.