QComboBox::insertItem() not honoring id?

[mikro]

hi,
The Manual tells us:

void QComboBox::insertItem ( int index, const QString & text, const QVariant & userData = QVariant() )
Inserts the text and userData into the combobox at the given index.

therefore i would expect QCombobox to honor the ids i give it? Please see attached mini-project: it does not. (at least not Version 4.1.4 on Windows XP)
Is this normal? Is there a different Result on different Computers?