I found this interesting. The tabs were not showing up correctly in Google Chrome - (see screenshot image). The tabs displayed fine in Firefox and IE8 and 9
Eventually traced the fault to the way a jquery file used by another plugin was loading. (wp-content/plugins/lightbox-plus/js/jquery.colorbox-min.js) I'd set this file to load Asynchronously, and placed in the footer section. Other jquery files were loading normally in the header.
Changing the load for this file back to normal mode and header fixed the display.
Anyone finding this display issue with Social Media Tabs and Chrome check how Java files (not only the one mentioned here - all jquery files)are loading - especially if using a CDN plugin -
(Loading Java Asynchronously and from footer causes a lot of bugs)