e-newsletter ReferenceError: jQuery is not defined

Hi,
We are not getting the preview box loading the email, unless we save and revisit the newsletter edit page (loading the saved content). I see there is an error: ReferenceError: jQuery is not defined,
It shows, via firebug line 230 in customize.php?wp_customize=on&theme=iletter&newsletter_id=159&return=admin.php%3Fpage%3Dnewsletters
commencing with...
<span class="customize-control-title">{{ data.label }}</span>

I am using wp vers 4.1.1 and e-newsletter version 2.7.1.3

Any ideas would be greatly appreciated
Thanks
Mike