everybody is right. You didn't do a good job of describing the problem. "now what used to work no longer works" just isn't going to cut it. We need to know what isn't working. Does the CGI app run at all? Does it run but not produce the correct results? How exactly is not working? :)

If you add use warnings; right before no warnings 'recursion'; then any warnings would be added to the web server log (if it's running Apache then more than likely that file is /var/log/httpd/error_log or /var/log/httpd/ssl_error_log).

You said that "The database server was changed" and "The tnsnames.ora file has been edited to relect the new server name."
Are you saying that you are now using a database on a different server or that the hostname of the same database server has changed? If it's the latter then I hope who ever did it is familiar with the necessary steps to change the hostname of an Oracle database server.

Are you really using a mix of DBI and oraperl? I suspect that it did not get stripped out when the script was moved to DBI because I don't see any calls to "ora_" functions.

I see some more potential problems but I don't have time to write them up. Sorry.