Facing an SSL problem that I can't resolve from the FAQ (no replies)

Hello,

Ok so I've read this:
[piwik.org]

I've also browsed through the forms and the search isn't pulling up what I need so please do not tell me to rtfm.

Here is my tracking info:

<script type="text/javascript">
  var _paq = _paq || [];
  _paq.push(["setCookieDomain", "*.www.domain.com"]);
  _paq.push(['trackPageView']);
  _paq.push(['enableLinkTracking']);
  (function() {
    var u="//members.domain.com/external/piwik/";
    _paq.push(['setTrackerUrl', u+'piwik.php']);
    _paq.push(['setSiteId', 1]);
    var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
    g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'piwik.js'; s.parentNode.insertBefore(g,s);
  })();
</script>
<noscript><p><img src="//members.domain.com/external/piwik/piwik.php?idsite=1" style="border:0;" alt="" /></p></noscript>
<!-- End Piwik Code -->

However ssl isn't working. www.whynopadlock.com check tells me:
Insecure URL: http://members.domain.com/external/piwik/piwik.php?idsite=1
Found in: https://www.domain.com/

If i'm using a protocol relative URL why is my ssl not working as expected?

Thank you.