When I put an Image in the Page Header and I generate the report in PDF the Image comes out where I expect it, but when I change the format to HTML, the image appears in a different place (it seems the image is being place in the body of the report, it should be place in the table TD tag with the report heading)

Your image for HTML needs to be in a url form
img src = url

in PDF it is the Style sheet.

You will have to creat something like

-IF &OUTPUT EQ 'HTML' THEN GOTO HTMIMG ELSE GO TO PDFIMG