Try the updates:

yum --enablerepo=updates-testing update 'cups*' 'system-config-printer*'

PS. Would be useful to know the actual results in terms of which error message or behaviour you are actually seeing...

1. Attempted to click "Cancel RSS subscription" in http://localhost:631/admin.
2. Password dialog, entered 'root' and root password.
3. Rejects password, hit escape, error:
"401 Unauthorized

Enter your username and password or the root username and password to access this page. If you are using Kerberos authentication, make sure you have a valid Kerberos ticket."

system-config-printer reads
"Unauthorized request (addPrinter)

You are not authorized to carry out the requested action."

Both cups and system-config-printer updated from updates-testing.

Is this a fresh install, or an upgrade?

What's in /var/log/cups/error_log?

Fresh install. But this also occurs on my upgraded F11 laptop.

"E [23/Jun/2009:11:17:33 -0500] cupsdAuthorize: pam_authenticate() returned 7 (Authentication failure)!" comes up on that login attempt.

Please humour me and triple-check that you have the correct password.

Can you also please try this as a non-root user?:

/usr/sbin/lpadmin -U root -p foo -E -v /dev/null

Everything's working for me (and others)...

(In reply to comment #6)
> Please humour me and triple-check that you have the correct password.
> 
Have done. Typed in plain text in a terminal, copied, ran "su -", pasted, logged in as root. Went to localhost:631, did adminy stuff, password failed.

> Can you also please try this as a non-root user?:
> 
> /usr/sbin/lpadmin -U root -p foo -E -v /dev/null
> 
That also failed.

Please attach /etc/cups/cupsd.conf, /etc/pam.d/cups, and /etc/pam.d/system-auth.

Created attachment 349116 [details]
cupsd.conf

Created attachment 349118 [details]
pam.d/cups

Created attachment 349119 [details]
pam.d/system-auth

Same here.

OK, next:
1. Run 'service cups restartlog' as root
2. Try the lpadmin command from comment #6
3. Attach /var/log/cups/error_log here, as well as any messages logged to /var/log/messages at the time you ran lpadmin

[root@deathray ~]# cat /var/log/cups/error_log 
E [23/Jun/2009:20:54:32 -0500] cupsdAuthorize: pam_authenticate() returned 7 (Authentication failure)!
E [23/Jun/2009:20:54:34 -0500] cupsdAuthorize: pam_authenticate() returned 7 (Authentication failure)!

/var/log/messages says nothing new as the cause of this.

'cupsctl --debug-logging' and try again.

(In reply to comment #0)
> Additional info:
> I also can't add a printer with system-config-printer when running as root
> (with sudo).  

(That part is bug #447266.)

Created attachment 349269 [details]
/var/log/cups/error_log

/var/log/messages still said nothing.

Is your root password longer than 32 characters?  Can you try changing it to something simpler, temporarily, to see if it is something about that particular password?

It is longer than 32 characters. Making it shorter fixes this bug. :/

It currently has this:

#if HAVE_LIBPAM
typedef struct cupsd_authdata_s         /**** Authentication data ****/
{
  char  username[33],                   /* Username string */
        password[33];                   /* Password string */
} cupsd_authdata_t;
#endif /* HAVE_LIBPAM */

Probably that should be:

#if HAVE_LIBPAM
typedef struct cupsd_authdata_s         /**** Authentication data ****/
{
  char  *username,                   /* Username string */
        *password;                   /* Password string */
} cupsd_authdata_t;
#endif /* HAVE_LIBPAM */

with allocators/deallocators for storage sizes of sysconf(_SC_LOGIN_NAME_MAX) and sysconf(_SC_PASS_MAX) respectively.

Reported upstream.  Closing this bug report as it has an easy work-around.

Wonderful, this is still an issue with cups-1.5.2

For anyone googling, https://www.cups.org/str.php?L2856

mike: 20:57 Feb 15, 2012
Fixed in Subversion repository.

1.6-feature