...or even to verify/debug my script?

Glad to, but you need to show the code. First, check your server's error log. Also, upload again, making certain that ftp is in ascii mode (otherwise you may get "File does not exist" because of name confusion by a spurious ^M).

After Compline,
Zaxo

The easiest thing to do is look in the httpd error log to see what errors your script is generating.

If that doesn't work, or you need more information, upload a small shell script like this:

#!/bin/sh -x

printf "Content-type: text/plain\n\n"
exec 2>&1

./your_script.cgi
echo "Exit status: $?"
[download]

Another technique is to upload a small script, say:

#!/usr/bin/perl -w

use strict;

print "Content-type: text/html\n\nThis is a CGI script.\n";
[download]