Rails - Feb 2006 - FastCgiExternalServer vs. static/dynamic

I''m trying to switch to the "external" fcgi method.

In httpd.conf, this works:
FastCgiServer "/tmp/rubystuff/testapp/public/dispatch.fcgi" 
-idle-timeout 20 -processes 4
FastCgiConfig -maxClassProcesses 2 -maxProcesses 2 -minProcesses 1 
-processSlack 1

This fails with an error (the public/500.html page is returned):
FastCgiExternalServer   "/tmp/rubystuff/testapp/public/dispatch.fcgi" 
-idle-timeout 20 -host localhost:19999

For the external, I am also starting
$ cgi-fcgi -start -connect localhost:19999 
/tmp/rubystuff/testapp/public/dispatch.fcgi 2

But there are no other changes to the configs.

Frthermore,
$ ps ax  | grep fcgi
  6749 pts/0    S      0:03 /usr/bin/ruby 
/tmp/rubystuff/testapp/public/dispatch.fcgi
  6750 pts/0    S      0:03 /usr/bin/ruby 
/tmp/rubystuff/testapp/public/dispatch.fcgi
  7097 pts/1    S+     0:00 /usr/bin/vim ./public/dispatch.fcgi
  7166 ?        S      0:00 /usr/sbin/fcgi- -k start

And,
$ netstat -an | grep 19999
tcp        0      0 127.0.0.1:19999             0.0.0.0:* 
     LISTEN


Could anyone suggest a possible remedy?

Thanks very much,
Jim