can't get Google to support my backstretch

I’m having a problem getting jquery backstretch to run from the Google library. I’m using this code:

<script type=”text/javascript” src=”https://www.timbaggaley.co.uk/js-includes/jq_backstretch/lib/jquery-1.4.2.min.js”></script&gt;
<script type=”text/javascript” src=”https://www.timbaggaley.co.uk/js-includes/jq_backstretch/jquery.backstretch.js”></script&gt;
<script type=”text/javascript”>
$.backstretch(“IMAGE URL”, {speed: 150});
</script>

In my test page at: https://timbaggaley.co.uk/backstretch/

It works fine as I am hosting the libraries on my own site. When I swap the first two lines of code for the google hosting address:

<script type=”text/javascript” src=”https://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js”></script&gt;
<script type=”text/javascript” src=”/jquery.backstretch.min.js”></script>

I lose my backstretch image. I’m no programmer but I’m an expert at copy and paste, and I’ve used code from other sites which work fine using the Google-hosted library, but i cannot get it to work for me. This test page is hand-coded but I have also used the backstretch code with the same problem in WordPress. Host the library myself and it works, hook up to Google and it fails.

What am I missing?
Thanks
Tim, London