This is a minor annoyance, but it still bugs the hell out of me.

I am using XFCE4 version 4.10.1,
Running on Debian Stable (version 8.9)
If it matters (it probably doesn't) I am using an Nvidia graphics card (GeForce GTX650), running driver version 375.66

I cannot find any useful information on linuxquestions.org or duckduckgo.com

I have two monitors (both 1920x1080)

When I use Steam on KDE4 or fluxbox, I get the games running on the left monitor.

When I use XFCE4, the games run on the right monitor.

Yup! That is the whole annoyance. Can anyone suggest a way to run the games on Steam to use the left monitor when using XFCE4?

Seriously, this has got to be a configuration file within XFCE4, but hell if I know how/what to modify the config file.

Thank you for you assistance in this matter.

{{Yes, it is about playing games... sorry.....}}

Try using nvidia-settings program to set up the monitors. If you run it as root you can save the settings.

Yup....
Did that.

That is why I think the annoyance is an XFCE problem and not a system problem, since it works fine on KDE4 and Fluxbox.

I'm guessing that either nowhere is a primary display explicitly specified, and/or that in XFCE there may need to be or done differently. Via the /etc/X11/xorg.conf created when you installed the NVidia driver you can specify which display should be primary. One can also specify which is primary using xrandr. It's probably easier to give arandr a try using XFCE first, the result of which would be user-specific. The xorg.conf method would apply to all users, while the xrandr method could be either global or user-specific, depending on how and when run.

OK. I will give that a try/look.

Thank you.

Should have a "Display" configuration tool off the menu...

OK, I _finally_ figured it out.

XFCE settings
"Window Manager Tweaks"
"Focus" tab
Click on "Bring window on current workspace"

It seems to work in my single test.

Thank you all for your advice.
I will tag this thread as [SOLVED].

PS: I hate configure tools........

Glad it worked out!