QTreeWidget, i cant see the items

I add items to a treewidget but i cannot see them
i am usings qtjambi, here is the code, the libraryTree is the QTreeWidget

Code:

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QTreeWidgetItem allItem = new QTreeWidgetItem(libraryTree);
        allItem.setText(1, "All");
        libraryTree.addTopLevelItem(allItem);

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using this i release that it never get past the second line until i close the window

Code:

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System.out.println("Add item");
QTreeWidgetItem allItem = new QTreeWidgetItem(libraryTree);
System.out.println("1");
allItem.setText(1, "All");
System.out.println("2");
libraryTree.addTopLevelItem(allItem);
System.out.println("The item has been added");

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output:

Code:

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Add item
QObject::startTimer: QTimer can only be used with threads started with QThread
QObject::startTimer: QTimer can only be used with threads started with QThread
1
2
The item has been added

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what thread and timer has to do with that?