With my DSO setup, I found that I needed to change the ownership of all files in the website directory to nobody:nobody before the setup wizard would stop reporting that files and folders were not accessible. This was after modifying the wp-config.php file using the instructions above under ‘Optimum Choice ~ The Script Owner ID & the File Owner ID Match’. The script and file owners did already match, but it seems they must both be ‘nobody’. Maybe this might help someone else?
chown -Rv nobody:nobody public_html/
Seems to be all up and running now though!
James 