for https, use siteurl() function not getoption('siteurl')

http://codex.wordpress.org/Function_Reference/site_url
“The site_url template tag retrieves the site url for the current site (where the WordPress core files reside) with the appropriate protocol, ‘https’ if is_ssl() and ‘http’ otherwise.”

http://codex.wordpress.org/Function_Reference/get_option(‘siteurl’)
This function has been deprecated. That means it has been replaced by a new function or is no longer supported, and may be removed from future versions. All code that uses this function should be converted to use its replacement if one exists. See also wp-includes/deprecated.php.
Use any of these functions instead.

Diff fix from
source:social-media-widget/trunk/social-widget.php@662156
14c14
< define(‘SMW_PLUGINPATH’,get_option(‘siteurl’).’/wp-content/plugins/’.plugin_basename(dirname(__FILE__)).’/’);
—
> define(‘SMW_PLUGINPATH’, site_url(‘/wp-content/plugins/’.plugin_basename(dirname(__FILE__)).’/’ ));

http://wordpress.org/extend/plugins/social-media-widget/