redgracemedia, you should start by disabling all the other plugins you’re using and see if the AddThis plugin works when it’s the only plugin running. If it does, reënable the other plugins you use one by one, testing to see if one of them breaks the AddThis functionality. Then you can begin to diagnose the problem.
Root Relative URLs also created problems with the XML sitemap plugin, rendering it effectively useless. We made modifications in the XML Sitemap to correct the output going to Google et al.
We ended up dropping AddThis because we weren’t actually seeing any shares from the site. 🙁
Thanks! I’ve just sent an email along.
