Description of problem:
I installed FC6 in a second HD, copied all sendmail configs (same sendmail 
version 8.13.8, copied send»»» mail.mc, authinfo, etc), did a make, m4, etc, 
restarted sendmail. I only want to use sendmail to d»»» eliver email to the 
real
smtp server. But the emails are rejected with the error:
                                                                                                      
<<< 530 5.7.0 Authentication required
554 5.0.0 Service unavailable

The EXACT same authinfo, sendmail.cf, etc files still work perfecty in FC5.

Version-Release number of selected component (if applicable):
sendmail-8.13.8-2

How reproducible:
$ sendmail -Am -t -v < test
<xxxx@xxxxx>... Connecting to smtp.xxxxxx. port 587 via relay...
220 smtp.xxxxx ESMTP Sendmail 8.13.1/8.13.1; Sun, 26 Nov 2006 18:12:29 -0200
>>> EHLO Antares.xxxxx
250-smtp.xxxxxx Hello antares.xxxxxxx [147.65.4.179], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE 7100000
250-AUTH DIGEST-MD5 CRAM-MD5
250-STARTTLS
250-DELIVERBY
250 HELP
>>> STARTTLS
220 2.0.0 Ready to start TLS
>>> EHLO Antares.xxxxxx
250-smtp.xxxxxxxxxx Hello antares.xxxxxx [147.65.4.179], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE 7100000
250-AUTH DIGEST-MD5 CRAM-MD5 LOGIN PLAIN
250-DELIVERBY
250 HELP
>>> MAIL From:<xxxx@xxxxxxxx> SIZE=38
530 5.7.0 Authentication required
Closing connection to smtp.xxxxx.
>>> QUIT
221 2.0.0 smtp.xxxxxxx closing connection

That is, THERE IS NO AUTH PLAIN transaction.

Steps to Reproduce:
1. Try to use smtp auth

Actual results:
Email rejected with "Authentication Required"

Expected results:
Email delivered.

Additional info:
In the /var/log/maillog file I have this:

Antares sendmail[21748]: AUTH=client, relay=smtp.xxxx [147.65.1.27], authinfo 
failed

So, for some reason, the authinfo feature is not working anymore.
See the sendmail.mc file attached.
I tried modifying/commenting/uncommenting the lines with TRUST_AUTH_MECH, 
define(`confAUTH_MECHANISMS'), etc, same results.