In HTML forms, name and ID are entirely independent (although their descriptions as id=name and name=cdata(control name) can be confusing), and can share the same value. This is often done with form elements (as a just-in-case for browsers, and ease of use for the developer). Prince treats these as an error even though it is valid:

<p><label for="waystohear">How did you hear about us:
<select name="waystohear" id="waystohear" size="3" multiple>
	<option value="search" selected>Search engine</option>
	<option value="friend">Word of mouth</option>
	<option value="advert">Ads</option>
</select></label></p>

Prince displays an error:
prince: http://www.example.com/:1778: error: ID waystohear already defined

(Using 6.0r1 on windows XP)

This is a known issue with the HTML parser, and should not affect XML and XHTML documents. We are working to improve our support for HTML in Prince for future releases.

Ok, so long as you are aware of it It doesn't seem to hurt at all, just makes it look strange when converting some of my pages.

Thanks for the reply.