xset on startup not saved

Ubuntu 14.04.03 LTS with i3wm.

I am trying to make my monitor "sleep" after some period of time. This is possible, but only typing it manually in terminal, any try to automate that fails, and monitor never goes off.
xset wont take changes from startup scripts, neither cronjobs(single line, executable scripts), "Startup applications", .xinitrc.

xset q says that dpms is enabled, but the values for standby, suspend and off are all 0. There is no problem setting them from terminal, only from scripts.