I’m sorry I WAS having this error with a different “Like” button plugin.
I am happy to report after deactivating that plug-in and then trying a few others, I decided to reactivate the initial plug-in, “Facebook Social Plugins.”
The problem I listed above has disappeared.
Here is the link to the plug-in I am using once again:
http://wordpress.org/extend/plugins/facebook-social-plugins/
I am having a similar problem except I get a red “Error” at the end of the “You like this” line. Clicking on the red “Error” brings up a Facebook pop up window that contains this:
You failed to provide a valid list of administators. You need to supply the administors using either a “fb:app_id” meta tag, or using a “fb:admins” meta tag to specify a comma-delimited list of Facebook users.
