The issue relates to the installation mentioned in the following thread "umbraco.config File Locking in Multi-site installation without load balancing"

I have another issue with the installation that is setup to notify editors of Publish actions on the main site. The notifications are sent multiple times (once for each site in the installation). I think the reason for this is because of the webservice notifications sent to each site to force them to update their cache. Can anyone confirm if the same issue occurs in load balanced scenarios?