When I compile the KDE editor example of chapter 13 I get the following 
linking error:
g++ -o editor obj/main.o obj/editorwindow.o -Llib -L/usr/X11R6/lib -
L/opt/kde2/lib -lqt -lXext -lX11 -lm -lkdeui -lkdecore -lkfile
editorwindow.o: In function `EditorWindow::EditorWindow(int)':
editorwindow.o(.text+0x42): undefined reference to 
`EditorWindow::KXMLGUIClient virtual table'
editorwindow.o(.text+0x49): undefined reference to 
`EditorWindow::QPaintDevice virtual table'
editorwindow.o(.text+0x50): undefined reference to 
`EditorWindow::KXMLGUIBuilder virtual table'
editorwindow.o(.text+0x57): undefined reference to `EditorWindow virtual 
table'
editorwindow.o: In function `EditorWindow::~EditorWindow(void)':
editorwindow.o(.text+0x792): undefined reference to 
`EditorWindow::QPaintDevice virtual table'
editorwindow.o(.text+0x799): undefined reference to 
`EditorWindow::KXMLGUIBuilder virtual table'
editorwindow.o(.text+0x7a0): undefined reference to `EditorWindow virtual 
table'
editorwindow.o(.text+0x7b0): undefined reference to 
`EditorWindow::KXMLGUIClient virtual table'
collect2: ld returned 1 exit status
gmake: *** [editor] Error 1

this error has been reported before on other sites for other programs but 
I could not find a solution for it. Has anyone an idea? Thanks in advance.

Sergio Millich