Error running "nvidia-settings --load-config-only" to setup TwinView config

Binary package hint: nvidia-settings

I have been trying to setup my computer to use nvidia twin view and I can configure it just fine using nvidia-setting by hand. However if I try to reload that configuration automatically (so I don't have to do it by hand every boot), I get an error message.

$ nvidia-settings --load-config-only

ERROR: The attribute 'XVideoSyncToDisplay' specified on line 53 of
       configuration file '/home/amp/.nvidia-settings-rc' cannot be assigned
       the value of DFP-0 (the currently enabled display devices are DFP-1 on
       magdalene:0.0).

The problem seems to be that the secondary must be enabled for "nvidia-settings --load-config-only" to configure it. However when using the nvidia-setting GUI by hand I can simply select the disabled display and click configure and set it up. It seems that "nvidia-settings --load-config-only" should be able to do this automatically.

It appears to me that there is information missing from .nvidia-settings-rc. Maybe nvidia-settings is failing to save some settings to the file. This is also shown by the fact that if I configure my displays differently (to clone instead of be next to each other say) and then run "nvidia-settings --load-config-only" the command does not print an error but it also does not change the monitor layout.

This is especially a problem because nvidia-settings is unable to generate a xorg.conf. So that there is no GUI way to configure twin view so that it will presist through a logout/login cycle.

Attached are some config files that might be useful.

PS: This is related to bug #108060