pam_authenticate error 7

[Jim Avera]

Hi,
I'm trying to enable CUPS web admin access using the regular /etc/passed file (not /etc/cups/passwd.md5).  However, no matter what I enter into the login dialog access is denied and error_log says

  E [...] IsAuthorized: pam_authenticate() returned 7 (Authentication failure)!

I've tried both root and non-root user names.
Incidentally, I can "telnet localhost" and successfully log in as an non-root user, but root telnet logins are not allowed.

If I set 'AuthType None' I can connect to the admin server successfully.

My browser is Firefox 1.0.

CONFIGURATION:
SuSE 9.1 linux stock installation.
rpm -q cups says "cups-1.1.20-108.13"

/etc/cups/cupsd.conf contains (excluding blank & comment lines):
LogLevel info
Printcap /etc/cups/printcap
User lp
Group lp
RunAsUser Yes
Port 631
BrowseAllow @LOCAL
BrowseDeny All
<Location />
  Order Deny,Allow
  Deny From All
  Allow From 127.0.0.1
  Allow From 127.0.0.2
  Allow From @LOCAL
</Location>
<Location /admin>
  AuthType Basic
  AuthClass User
  Order Deny,Allow
  Deny From All
  Allow From 127.0.0.1
</Location>

Does anyone have any suggestions?

Thanks in advance!
-Jim