I have been told that search engines can't read graphic based navigation links, so it is imperative to have text based navigation links.
Surely the spiders (or whatever they are) read the HTML code, and if the HTML code for a graphic based link contained code such as "href=http://www.mydomain.com/page2" then wouldn't the spider recognise that?
Admittedly my web tool generates more code for a graphic based link, but both graphic and text links have the href parameter which points to the web page in question.