If I press ctrl+alt+F8 I get what should be the second screen with a flashing curser in the top corner on the correct monitor.
The following appears in the Xorg.0.log and Xorg.1.log files frequently.
(II) Screen 1 shares mem & io resources
It looks like the first Xserver is using the seconds resourdes or something? There are no meaningful error messages in the logs.