phranque - 12:26 am on Sep 8, 2010 (gmt 0)

however, it would be stupid to place an image on its own within heading tags

unless the image contains text that is relevant to that heading.

Firstly, the ultimate heading of a page is the title, therefore you may reasonably have as many H1 headings as you wish and undoubtedly you could have an H6 above the second H1.

title is a meta element in the head of the html document - headers are on-page content.
the title is not part of the semantic structure of the document.
the headers help define the semantic structure.

... it would be stupid to place an image ...

... ignore idiots who tell you that this or that is wrong.