(SOLVED) - Unable to connect to dbispconfig
I finally had the time to dig and resolve this problem.
It was a conflict between the Apache module of Webdmin and an update for Apache. The default directory for virtual sites changed. Add to that, the ispconfig.vhost settings didn't seem to change the root document directory for the :8080 vhost correctly (I'm still looking into this).
I don't know if this is a Centos (5.9), Apache, Webmin thing or not, but after I moved the "ispconfig" symlink file from /var/www/ispconfig to /var/www/html - everything started working correctly.
Maybe this information will help someone else, or maybe this is just a freak "1 in a million" event that I had the pleasire of experiencing - in any case - Till, thank you for all of your assistance and PLEASE KEEP UP THE GOOD WORK!
p.s. - The "unable to connect to database" error was due to the fact that there was an old, unused website located in /var/www/html that had bad DB credentials configured. I replaced it with the ispconfig symlink file.