[arch-general] my Arch box randomly becomes irresponsible

[Not To Miss]

Dear Arch users,

I have latest Arch installed on my desktop at work. In recent two weeks,
the system randomly "suspends" at night (I call it "randomly" because it
didn't happen every night. And it seems to happen after a random period
idle time) when I am off. I can't wake it up in the next morning thru mouse
or keyboard.

I tried to disable suspension and hibernation by editing
/usr/share/polkit-1/actions/org.freedesktop.upower.policy to change
from
<allow_active>yes</allow_active>
to
<allow_active>no</allow_active>

But it doesn't work.

While I call it "suspend", I am not sure it suspend to RAM or hibernate to
disk, because I find the CPU fan and power fan still spin normally. RAM
light is also on. So it might be a video driver / setting related issue.
For your information, I am using nvidia-302.17-2-x86_64 and have dual
monitor set up with nvidia-utils-302.17-1-x86_64

This really bothers me a lot. Any help is appreciated. Thanks!

-- 
Best,
Zech