Ok, solved the problem with your help. I used the PLESK pages to create a second user and used the above test php file to login to the database. What I found is that this system accepts a Database name and Database user in ALL LOWER case ONLY. This is in spite of the fact that I asked tech support to initially create everything using upper-case.
Once I switched to all lower-case, I got past the check database settings page.
Not sure if that is only a restriction on this server, but a note in your install instructions could be useful.
Thanks for the help!
