And bingo, I found the actual problem.
As previously noted, the wrapper was written thusly:
exec /usr/bin/php -d magic_quotes_gpc=off session.save_path=/usr/local/ispconfig/server/temp
I took a look at a couple of the other websites that ispconfig had created, as well as the master php-fcgid-starter wrapper...
they all called /usr/bin/php-cgi instead of /usr/bin/php
I made this change and it fixed the issue completely.
I also want to note, for anyone else that might use this as reference in the future the comment on this page:
Never use PHP_FCGI_CHILDREN with mod_fcgid
Submitted by George Negoita (not registered) on Wed, 2009-09-09 15:25.
I've spotted another problem in this setup. You should never use PHP_FCGI_CHILDREN while using mod_fcgid, because mod_fcgid will never send more than one request at a time to a running php process.
You cand find more info here: http://wherethebitsroam.com/blogs/je...hpfcgichildren
While this didn't have anything to do with my problem, in my search for a solution I'd come across several documents stating that this needed to be set, when in fact it doesn't.