Comment # 21 on bug 1022050 from Stefan Dirsch

(In reply to Cameron Rapp from comment #20)
> Since this patch has been added it has introduced a new issue. Monitors will
> no longer power off according to the power management settings but will only
> blank instead, even if blank is set to "never". A "xset dpms force off"
> command will succeed however. Reverting this patch fixes the issue.

This sounds completely unrelated to the patch. Other patches have been applied
on top of this meanwhile.

But if things work with 

  xset dpms force off

this looks more like a regression in your desktop than a regression in the
Xserver.

I suggest to open a bugreport against the desktop component instead.