-- Add the missing virtual d'tors, there are pure virtual methods in the TreeBase class.

treebase.h

@@ -37,6 +37,7 @@ class TreeBase : public KListView
     TreeBase( QWidget * parent, KMFolderTree *folderTree,
         const QString &preSelection, bool mustBeReadWrite );
 	
+    virtual  ~TreeBase() {}
 
      const KMFolder * folder() const;
     /** Set the current folder */