QMessageBox Button Default Button selection not honored

When using the critical, information, question, or warning static methods in the QMessageBox class to create a QMessageBox dialog and passing in a default button, the default button is not guaranteed to be the highlighted button when the dialog is shown.

For example, the code:

QMessageBox::question(this, tr("Confirm Exit"), tr("Do you really want to quit?"), QMessageBox::No | QMessageBox::Yes, QMessageBox::Yes);

will display a QMessageBox where the "No" push button is highlighted instead of the "Yes" push button. It appears that the "Yes" push button is momentarily highlighted when the QMessageBox is displayed but that the focus immediately goes to the "No" push button without any user input. If the default button passed is QMessageBox::No, the "No" push button is correctly highlighted as the default. It appears that the left-most button always receives the focus regardless of the default button parameter value in the static method parameter list.