The way I found this was when I was looking for pages that were created in a site I inherited, the original developer (for some unknown reason) did not turn on Publishing and created a new separate directory/library for the web pages. So, every time, I tried to edit a web part on a page, it would tell me (once I got through with the entire edit), that I needed to check the page out before making my edits. That drove me crazy.
So, later, I turned on Publishing, but some of the normal stuff that goes on when you do this did not happen. So, the ‘super user’ that needed to create new pages could not – she got the old ‘access denied’ message. But, this was rather easy to remedy.
What I did in this instance was navigate to the Master Page Gallery Library and give READ access to the Admin group she was in. And that was all it took!
All Things DotNet Discussed – Winforms/ASP.Net/SharePoint/WPF