QComboBox: Dropdown size appears to be limited even if setMaxVisibleItems() is called with a large number of items e.g. 10

The drop down list seems to be fixed in size even if the setMaxVisibleItems() is called on a combobox. This can be seen in line 107 here:
http://codepaster.nokia.troll.no/?id=11814 (it's currently commented out and there is another call to setMaxVisibleItems() on line 111.