Why am I getting a JSON dump when saving a node?
We were having this same issue on our company website. We have Administration Views installed, and use jQuery 1.8 as default version and 1.5 for admin pages.

As SomethingOn mentioned above, we were consistently seeing the JSON dump after filtering on the Find Content view, editing a node then saving. The URL paths all had 'views/ajax' in the query string of the node edit URL; e.g.,

/node/XXXX/edit?destination=admin/content%3Fq%3Dviews/ajax%26title%3D%26type%3DAll%26author%3D%26status%3D0%26vid%3DAll


What I ended up doing was turning AJAX off (under Advanced > Other > Use AJAX) for the Find Content view (Administration:Nodes). This removed 'views/ajax' from the node edit paths and resolved the issue for us.