This has NOT just started with 3.6, but now it seems a little more consistent and I'm able to repeat the behavior on both Chrome and FF for Mac. Safari does not show the path at the bottom of the browser.
Problem: after I click on an image, then click to close, the path to that image "sticks" even after the image has closed. It's always the URL path to the last image showing, this is now very consistant. If you click anywhere, other than another image, the sticky path disappears.
I downloaded another Colorbox plugin called "Simple Colorbox" and the problem does NOT exist. There is no sticky path left after the last image is closed.
For a better example I made a short screencast: http://screencast-o-matic.com/watch/cIjIrcVgYe
Thank you for taking a look!