Following a successful install and subsequent use of nvidia-340 - uninstallation of nvidia via Additional Drivers led to a reboot to a desktop at 640x480 px.
Investigation found an nvidia created file left on the system blacklisting nouveau, deleted file and rebooted to normal desktop.
Didn't think about ubuntu-reporting this - can try and replicate and apport-collect if it's of any use.
Following a successful install and subsequent use of nvidia-340 - uninstallation of nvidia via Additional Drivers led to a reboot to a desktop at 640x480 px.
Investigation found an nvidia created file left on the system blacklisting nouveau, deleted file and rebooted to normal desktop.
Didn't think about ubuntu-reporting this - can try and replicate and apport-collect if it's of any use.