Issues downgrading to g-i-t 2.14

I downgraded my test installation under /opt with jhbuild from HEAD to
gnome-2-14 branch of g-i-t (I've to produce screenshots for manuals).

I'm experiencing the following issues:
      * Icon for "Computer" nautilus location is missing at all sizes
        (is showed the old GNOME1-style paper sheet instead)
      * a 24x24 icon scaled up to 48x48 is showed for MP3, PNG and JPEG
        files
      * same for AVI files, but the icon is a paper sheet with a red
        connector over it
      * GTK+ stock icons are not showed on toolbars. This happens only
        on toolbars: menu icons and dialog buttons are OK[1]

Launching gedit from the terminal, it shows

        sys:1: GtkWarning: Error loading theme icon for stock: failed to
        open file /opt/gnome/share/icons/gnome/24x24/actions/gtk-*: no
        such file or directory
        
Do I've to re-build gtk (and gtk-icon-cache)?