Windows: Double-clicking the control box in the upper-left corner of an MDI form window does not close the window

Double-clicking the control box in the upper-left corner of an MDI form window does not close the window in Qt 4.3.0.

This can be seen in either Qt Designer or in the MDI example.

The standard behavior in an MDI application is for the window to close.

Reopened, still able to reproduce in 4.4.3.