One of my clients today was having a problem editing content on their site that was initially created by me when I was logged in as admin (user 1). The solution wasn't immediately obvious to me as the role I created for the employees of the company had access to create and edit content for that particular content type. I then realised I had changed the input format for some of the nodes to Full HTML. So the fix was to add the tags the employees needed to the Filtered HTML input (admin/settings/filter).