Hi Arnuschky,
I use the lock command only.
Keeping the DPMS display off time the same as the screen saver activation time should do the trick in most cases.
However, for programs that inhibit the screen saver but do not cause input events (such as a movie player) I am not sure if they also inhibit DPMS display off. Someone want to test this? Do for example xset dpms 0 0 60 and start mplayer or totem, and see if the screen goes off in 60 secs.
Normal behaviour can be achieved with xset dpms 0 0 0 (no shutoff).