One more update... (after playing some more with xfce)
Normally I lock the screen manually using the keyboard-shortcut (which results in the screen being locked by the xfce lock.)
If instead I switch user, then the "xscreensaver" kicks in instead of the xfce lock.
Returning to my own user lateron then means that I enter password on the dm, then again into xscreensaver's dialog.
The problematic case seems to be, when I manually start the xfce-lock (e.g. using the keycombo), and lateron the xscreensaver activates itself based on idle-time.
While the xfce lock is active, it just ought to *suppress* the xscreensaver (or light-locker, whatever) and the problem should be solved.
One more update... (after playing some more with xfce)
Normally I lock the screen manually using the keyboard-shortcut (which results in the screen being locked by the xfce lock.)
If instead I switch user, then the "xscreensaver" kicks in instead of the xfce lock.
Returning to my own user lateron then means that I enter password on the dm, then again into xscreensaver's dialog.
The problematic case seems to be, when I manually start the xfce-lock (e.g. using the keycombo), and lateron the xscreensaver activates itself based on idle-time.
While the xfce lock is active, it just ought to *suppress* the xscreensaver (or light-locker, whatever) and the problem should be solved.