I had this problem as well, I disabled some other facebook like plugins I was using and it fixed the issue.
Plugins:
‘Like’
‘Facebook Like Button’
Now when I was first testing this I turned off the one I thought was causing the problem, eg. My sharedaddy plugin was working on my index page so I disabled the plugin that I was using on the posts & pages.. this didn’t work.
I think what was happening is the plugin that was working index and set to ‘hide’ or not show up on posts & pages, so maybe this was causing to hide sharedaddy.
meh.