Well... I think nothing has changed since the first report of this bug.
Steve, source of the confusion is... there are two "modes" of full screen:
a) Browser forced (user pressed F11) full screen - browser hides system toolbar, caption, status bar, but the display of the content (so called "client area") is unchanged, only re-rendered to utilize enlarged display area. Client are is not aware of browser being run in full screen mode. This mode works fine.
b) Client forced full screen (full screen icon on Panoramio photo explorer navigation toolbar) - client changes its operation mode (hides amost empty toolbar with logo and users avatar and settings button, puts photo explorer navigation toolbar into autohide mode) + forces browser to full screen mode - same action as described in a).
In this mode, although photo explorer navigation toolbar is visible, it is not clickable. Looks like transparent from the point of mouse input. Click within photo explorer navigation toolbar are translated as clicks on photo itself (e.g. double click enlarges photos). For me, intermezzo with alternate keybord input (keys left/right) does not help to revive toolbar (however keyboard controled navigation works fine).
There are more bugs in photo explorer - summary:
a) photo explorer does not work at all in client forced full screen mode
b) "Change" option for navigation in explorer does not work - can bu used only to jump to popular photos set
c) switching to / out of full screen mode sometimes does not repaint properly client area at proper place/ resolution (photo is shifted, cropped, does not utilize whole screen) - this is a bit random, sometimes it works fine. No matter which "full screen mode" you use - both have glitches.
d) Zoom navigation window shall disappear out of view (fade) if there is no mouse activity... often it "flickers" instead of that
e) Photo explorer navigation toolbar shall autohide in client forced full screen mode - but it does not. I think it has worked some time ago, but now this navigation toolbar is pinned to photo and sometimes obscures part of the view (see c)
f)Not sure if photo title has to have "autohide" feature too...
I am talking about Chrome. Beahviour in other browsers may differ.