monitor "xset dpms" stopped working in 5.1

[Guy Middleton]

I recently upgraded my system from 3.1 to 5.1.

I have this in my .xsession:

	xset s 300 s blank dpms 1200 3600

So after 20 minutes, the monitor would go into "standby" mode, then after an
hour into "suspend" mode.

Now in 5.1, it will go standby, but never suspend.  Even whey I do
"xset dpms force suspend", it goes into standby and stays there.

An "xset q" in this state says the monitor is in "Suspend" state, even though
it isn't.

Has anybody seen this before?  Is there a fix?