If you're using ‎Panels‎ to output your content type and you enable the ‎Plus 1‎ module, you may notice the Plus 1 widget doesn't appear when you view your node.

If you don't see the widget, then you've probably enabled 'no extras' in your Panels node template override. If there's no other reason for enabling this option, you can simply uncheck the box and the Plus 1 widget will appear when you view your node.

If you do need to keep this unchecked, you can add a snippet to either your theme's node.tpl.php or node-customtype.tpl.php.