Proper dual monitor set up somewhere?

[otisklt]

If the nvidia config works correctly then try to use it to reset the desktops.
A recent kernel update seemed to knock my multi-display config out of whack in a similar way and the system settings would not allow me to fix it properly but the displays manager in the amd config worked to restore the setup.

Otherwise uninstall the video drivers and do a clean install of them.

[oshunluvr]

Must be something with KDE, a new profile didn't seem to work either. Guess I need to find out if that will be fixed in 15.10 or if I need to look elsewhere.

I'm unclear as to how you come to that conclusion. If it were Plasma5 (KDE), a clean user would likely be OK. It could be Plasma5 but it's more likely the display manager (SDDM), Xorg, the kernel/driver because it relates to monitor detection. xrandr doesn't show it, therefore something that loads prior to xrandr is the likeliest problem. KDE loads after xorg and xrandr is part of xorg not Plasma5. AFAIK, Plasma doesn't really do monitor detection, just allows you to change settings.

Installing Wily is a good idea. It might just go away with the newer kernel. Here's other things to try:

• Enable the xorg-edgers ppa and install the 355 nVidia driver (I'm using it without issue on a GTX 780).
• Boot to a live version (usb or cd) of 15.04 and see if your monitor works normally there.
• Actually read through /var/log/Xorg.0.log and ~/.xsession-errors and/or attach a copy of both to a post for review.
• Boot with one monitor attached at a time to verify they both work independently and copy the logs and xrandr output and save them for later comparison.

The most interesting thing is that while xrandr can't "see" the second monitor, some part of xorg does because the mouse cursor is active there - even though xrandr reports an active desktop size of only the one monitor. I'd love to get a gander at your Xorg.0.log. The answer (or at least the proper question) might be in there.

[elijathegold]

While not as likely to be helpful, a look through dmesg wouldn't hurt either.

[therelic]

Something everyone missed is that xrandr doesn't even try to detect or show any information on dvi-i-0 ( it looks for dvi-i-1 which doesn't exist. ).

Not sure why xrandr isn't finding a monitor that is there when xorg takes over.

[therelic]

Going to try the wily beta. See if that clears up the problems.