When displaying a larger hierarchy, e.g. displaying a filesystem hierarchy with all nodes expanded and mousing over
Strings to display TooltipTexts and sometimes clicking in the table, the UI stalls longer and longer trying to display
the tooltiptext of the string and never recovers. I've reproduced this on different platforms (XP, OS X) and with
different models.

For reproducing the bug you can use this in your TopComponent's constructor:

outlineView = new OutlineView();
FileObject fo = FileUtil.getConfigRoot();
try {
   DataObject dao = DataObject.find(fo);
   Node root = dao.getNodeDelegate();
   outlineView.setProperties(root.getPropertySets()[0].getProperties());
   explorermanager.setRootContext(root);
} catch (DataObjectNotFoundException ex) {
   Exceptions.printStackTrace(ex);
}
add(outlineView, BorderLayout.CENTER);

and to expand all nodes:
    @Override
    protected void componentShowing() {
        super.componentShowing();
        if (firsttime) {
            firsttime = false;
            expandAllNodes(explorermanager.getRootContext());
        }
    }

    private void expandAllNodes(Node root) {
        outlineView.expandNode(root);
        Children children = root.getChildren();
        Node[] childNodes = children.getNodes();
        for (int i = 0; i < childNodes.length; i++) {
            Node node = childNodes[i];
            expandAllNodes(node);
        }
    }


Workaround:

1. Disabling editors fixes the above problem, but it's not really a workaround, because you're loosing functionality
2. Use TreeTableView - also not really a workaround