I had a similar problem with the gnome "Lock Screen" applet. Both xscreensaver-command and gnome-screensaver-command use the "-lock" parameter. I created a symbolic link xscreensaver-command to gnome-screensaver-command to fix this:
" sudo ln -sf /usr/local/bin/xscreensaver-command /usr/bin/gnome-screensaver-command "
I had a similar problem with the gnome "Lock Screen" applet. Both xscreensaver- command and gnome-screensav er-command use the "-lock" parameter. I created a symbolic link xscreensaver- command to gnome-screensav er-command to fix this:
" sudo ln -sf /usr/local/ bin/xscreensave r-command /usr/bin/ gnome-screensav er-command "