I finally managed to understand some of my problems and I found a satisfactory solution to 2 and 3:

2. The supposed 'presentation' mode does not work. LCD screen in laptop is still turned off after 10 min... Naturally VLC's own inhibition of power manager doesn't work either.

3. I wanted to watch a video online that normally lasts like 40 min, so I changed the threshold for putting the display of standy from 10 min to 50 min. Sadly, after 10 min the screen went blank.

The problem is that screen blanking is not turned off by xfpm. The output of the command 'xset q' showed me that my screensaver blanking was activated (despite NOT having xscreensaver installed). The best solution I found was to turn it off entirely using a configuration file in /etc/X11/xorg.conf.d/ with this in it:

Section "ServerFlags"
	Option "BlankTime" "0"
EndSection

Alternatively, the command 'xset s off' or simply 'xset s noblank' can turn off the screen blanking.

With this annoying blanking out of the way, xfce power manager worked as expected. I can now change the time for the monitor to go on standby and go fully off. Presentation mode works as a charm as well.

The only thing that I can't seem to get working is the auto-brightness adjust. But this one does not bother me too much.

Thank you - that "ServerFlags" code worked great for me -- no more screen blanking after 10 minutes!

https://bugzilla.xfce.org/show_bug.cgi?id=8840

The patch was posted to the debian bug tracker but apparently the debian devs didnt like the patch in its current state so there's been no movement there either.

Edit: oh, it seems that there is a patch available for the brightness bug ...

The problem is that screen blanking is not turned off by xfpm. The output of the command 'xset q' showed me that my screensaver blanking was activated (despite NOT having xscreensaver installed). The best solution I found was to turn it off entirely using a configuration file in /etc/X11/xorg.conf.d/ with this in it:

Section "ServerFlags"
	Option "BlankTime" "0"
EndSection

Alternatively, the command 'xset s off' or simply 'xset s noblank' can turn off the screen blanking.

With this annoying blanking out of the way, xfce power manager worked as expected. I can now change the time for the monitor to go on standby and go fully off. Presentation mode works as a charm as well.

The only thing that I can't seem to get working is the auto-brightness adjust. But this one does not bother me too much.

I can't seem to find much information about these issues on the internet. Which means it works more or less well for everyone.

Not necessarily. Sometimes people just don't bother to report that or use other hacks like disabling DPMS directly on xorg.conf.

First time posting on this forum. I've been using xfce 4.8 on Debian wheezy. It works great except for the the power manager which is giving me many problems:

1. The brightness control does not work. After the time of inactivity is elapsed the brightness is not adjusted accordingly. Adjusting it manually via the panel plugin or using 'xbacklight' works as expected. Gnome3 power manager has no issue with this (just to point out that it's probably not a hardware issue).

2. The supposed 'presentation' mode does not work. LCD screen in laptop is still turned off after 10 min... Naturally VLC's own inhibition of power manager doesn't work either.

3. I wanted to watch a video online that normally lasts like 40 min, so I changed the threshold for putting the display of standy from 10 min to 50 min. Sadly, after 10 min the screen went blank.

I had xscreensaver, but I uninstalled it. My user is part of the powerdev group. Using lightdm. Kernel 3.2.19

Problem is present with both 1.0.11 and 1.2.0 versions of xfpm.
Debian bug report: http://bugs.debian.org/676854

In bug report you can find a text file attached in the last message in the thread about the debugging messages while running xfpm 1.2.0

I can't seem to find much information about these issues on the internet. Which means it works more or less well for everyone. Please help!
I really really don't want to pull in gnome3-power-manager...

Thanks

Andres