DOCBOOK: "SYSTEM" specification required

[jvjena at cs dot tu-berlin dot de]

When compiling DocBook XML DTD V4.0beta1 with the 
Wordperfect 9 DTD-Compiler I get several error-message from the 
WP DTD-Compiler, all off the same type:

XML-Error:
Externe Entities müssen explizit eine SYSTEM-Kennzeichnung 
enthalten
(External Entities have to contain explicitly a SYSTEM 
specification)
Die folgenden Entity-Deklarationen sind in XML zulässig:
(The following entity declarations are allowed in XML:)
<!ENTITY ElmtSet1 PUBLIC "-//Corel//ELEMENTS subset//EN" 
"elements.dtd">
<!ENTITY ElmtSet1 SYSTEM "elements.dtd">
...

An example: The offending lines are:

Line 66 (->) from docbookx.dtd:

       <![%dbnotn.module;[
       <!ENTITY % dbnotn PUBLIC 
        "-//OASIS//ENTITIES DocBook XML Notations V4.0beta1//EN"
       "dbnotnx.mod">
->    %dbnotn;
        ]]>

associated with line 59 from dbntx.mod:

        <!NOTATION BMP		PUBLIC
        "+//ISBN 0-7923-9432-1::Graphic Notation//NOTATION
 ->     Microsoft Windows bitmap//EN">

I suppose I have to adjust the compiling catalog "compile.cat" but 
what information is required there?

Joachim voon Jena