Adaptive Image - cache issue with AEM6.1



We are experiencing and odd issue on a new site in development in which content cached from Publish is causing an error in Author.

We using the Adobe Managed Service for hosting. On their boxes the Dispatcher server is shared between Author and Publish but I still would not expect Author to be checking content cached by Publish.

The error in Author is a pop up that states: "Your request could not be completed because you have been signed off". The user is automatically signed back in (the Log In screen just briefly flashes on the screen). 

The component that seems to be triggering this is the Adaptive Image component. It may also potentially be associated with the cq:listeners node as the error appears on a page refresh.

Looking in Firebug the oddity is this. If the page being edited has not been cached the Post that occurs on the page refresh returns a HTTP 200 initiated by granite.js and all is good.

If the page content has been cached in Publish, the same operation in Firebug shows a HTTP 301 for granite.js and then triggers an HTTP 403 on the page.

I appreciate this is vague, but at this stage even just suggestion of what to look at would be appreciated. I don't even have a current theory about what is going on.