nvidia-settings and xrandr detect identical monitors differently on GTX 760

I am trying to setup dual head through DisplayPort (MTS) using an NVidia GTX 760. I have two identical monitors from ViewSonic but both X-server and xrandr are interpreting only one monitor correctly and the other falling back into an unacceptable default.

Output from xrandr -q

root@Saturn:~# xrandr -q
Screen 0: minimum 8 x 8, current 2560 x 1080, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
DP-1.1.2 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 598mm x 336mm
   1920x1080     60.00*+  59.94    50.00  
   1680x1050     59.95  
   1600x1200     60.00  
   1600x900      60.00  
   1440x900      59.89  
   1400x1050     59.98  
   1280x1024     75.02    60.02  
   1280x960      60.00  
   1280x720      60.00    59.94    50.00  
   1024x768      75.03    70.07    60.00  
   800x600       75.00    72.19    60.32    56.25  
   720x576       50.00  
   720x480       59.94  
   640x480       75.00    72.81    59.94    59.93  
DP-1.1.1 connected 640x480+1920+0 (normal left inverted right x axis y axis) 0mm x 0mm
   640x480       59.94*+
DVI-I-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
DVI-D-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)

I would be willing to force a particular setup with an explicit xorg.conf but all my attempts at doing so have failed so far. I have reverted to removing xorg.conf.

I have connected the single display port output from GTX 760 to a 4-way Club CSV-6400 hub. On the first two outputs from the hub I have connected DisplayPort to HDMI adaptors and from there, directly to the monitors. As I said before, both monitors are identical.

Debug pack attached.
nvidia-bug-report.log.gz (1.14 MB)