QSqlRelationalTableModel: cannot select rows from the related table, that were added after the initial population

I have a problem with QSqlRelationalTableModel in Qt 4.6.x
When inserting a new row to the referenced table AFTER initial population of the models,
the selection of that new entry in the referring table fails quietly.
May be a problem with the dictionary-population of QRelation ?

Reproduceable on Linux/Windows (try to select "Stuttgart" after 5 sec.) with the attached example application