-> [Sat Jan  8 15:03:03 2005] [error] (2)No such file or directory: exec
-> of /home/sean/www/cgi-bin/demo.cgi failed
-> [Sat Jan  8 15:03:03 2005] [error] [client 127.0.0.1] Premature end of
-> script headers: /home/sean/www/cgi-bin/demo.cgi
->
-> Those are the two error lines I'm getting when I try to load demo.cgi.
-> Apache is set with a ScriptAlias /cgi-bin/ /home/sean/www/cgi-bin/,
-> which is where demo.cgi is located.

Make sure that the program, at the top of demo.cgi, represented thusly:

        #! program

actually exists; you need to be able to execute that program from within
the default path.

If the program is unchanged, as in the Quixote distribution, it's
currently set to

#!/www/python/bin/python

which doesn't exist in any of the Linux distributions I'm familiar with.
In bash, you can use 'type python' to find out where the python you're
executing from the command line resides.

You should be able to execute './demo.cgi' from within
/home/sean/www/cgi-bin at the very least.

Note that

        #! /usr/bin/env python

(a common way to execute whichever python appears in your path)
often doesn't work for locally-installed python distributions, because
usually apache doesn't have /usr/local/bin in its default path.

hope that helps!

cheers,
--titus