Bug 67890 [PropertiesView] Exception when entries added to properties view
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertySheetViewer.java
Object el = children.get(i);
            if (!set.contains(el))
                createItem(el, widget, i);
        }
        
        if (widget == tree && oldCnt == 0 && tree.getItemCount() == 1) {
            tree.setRedraw(false);
            tree.setRedraw(true);
        }
        
        if (entry == rootEntry)
            childItems = tree.getItems();
        else
            childItems = item.getItems();
        
        
        
        for (int i = 0; i < newSize; i++) {
            Object el = children.get(i);
            if (el instanceof IPropertySheetEntry)
                updateEntry((IPropertySheetEntry) el, childItems[i]);
            else {
                updateCategory((PropertySheetCategory) el, childItems[i]);
                updateChildrenOf(el, childItems[i]);
            }
        }
        
        
        entrySelectionChanged();
    }