W3 Validation and heading tag problem

This is my breadcrumb, which I've wrapped with H1/H2, since (debatably) it's better for SEO:

<a href="$vboptions[forumhome].php$session[sessionurl_q]" accesskey="1"><span class="h1navbar">$vboptions[bbtitle] </span></a><h2 class="h1navbar">$navbits[breadcrumb]</h2> ? <h1 class="h1navbar">$navbits[lastelement]</h1>

And this is the error I'm getting:

The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").

document type does not allow element "h1" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag.

I really want to properly include H1 tags, and I have to assume that the breadcrumbs are the most relevant content to put there. What am I missing?