Inserting watermarks removes page numbers

I have a Word 2002 document which is 40 pages long. It has a table of contents on the third page. Each page has a page number following the table of contents. Each section is separated by section breaks (new page) but the numbers follow on from the previous section.

When I insert a text watermark and either print the document or refresh the table of contents, the page numbers revert to zero. Removing the watermark then printing or fresh the table of contents makes the page numbers appear again.

Has anyone got any clues?? I’m going round in circles!