If you click the mouse, or scroll the scroll-wheel without moving the pointer, then gnome-screensaver will detect the session as being idle. This is a limitation of X.org, but is worked around in newer versions of gnome-screensaver.
Saguarekin klik eginez gero, edo korritzeko gurpila erakuslea mugitu gabe korrituz gero, GNOMEren pantaila-babesleak saioa inaktibotzat joko du. X.org-en muga da hau, baina saiatzen ari gara konpontzen GNOMEren pantaila-babeslearen bertsio berriagoetan.