Stone Post,
There is no such thing as a "Word code" (I think you mean PC) .pdf.
1. Is it necessary for your watermark graphic to be the same size as the letterhead?
2. Are you in *Word Processing* or *Layout mode* ? This is announced after the document name in the top bar of the window.
3. It will be better for you to be in *Word Processing mode* there is virtually no advantage to be in Layout mode, especially for a document that will probably continue onto following pages.
4. See my instructions here:
http://discussions.apple.com/thread.jspa?threadID=2053050&tstart=0
Except instead of creating a text box, click on the
Shapes icon 6th from left on the
Toolbar and stretch it out as large as you need.
Peter