[Plugin: WP-Members] No emails

Since upgrading to WP-Members 2.7.4 no emails are being sent by the plugin (registration or approval). Nothing else has changed except the upgrade to WP 3.4. Other emails (contact forms etc are working ok).

Any thoughts please?

site is http://www.lewesoperatic.co.uk/

Thanks

http://wordpress.org/extend/plugins/wp-members/