I'm running Debian Wheezy using gdm3 as window manager and xfce4 as desktop environment.
Every so often, when I login, the desktop environment starts OK, but all windows are missing the title bar and are positioned at location (0,0).
Usually logging out and back in, or restarting gdm3 and logging in, fixes it, but today it didn't. I switched to 'GNOME classic' which works fine, indicating it's probably a setting in xfce4 that's got corrupted.
Short of just zapping every file in .config/ and .cache/ which refers to xfce, is there a simple fix/edit?