Kerberos authentication breaks admin.cgi

[bse]

I have tried to set up Cups 1.3.8 with Kerberos (Negotiate) as authentication mechanism. The authentication seems to be working, but any operation in the admin gui such as stopping a printer returns a blank page.

It seems that the server accepts me into the web gui, but something goes wrong when launching the admin.cgi program.

Has anyone seen this before?

In the logfile I get:

D [24/Jul/2008:10:23:00 +0200] get_gss_creds: Attempting to acquire credentials for HTTP at vmtest002.ita.chalmers.se...
D [24/Jul/2008:10:23:00 +0200] get_gss_creds: Credentials acquired successfully for HTTP at vmtest002.ita.chalmers.se.
D [24/Jul/2008:10:23:00 +0200] cupsdAuthorize: Authorized as bse at CHALMERS.SE using Negotiate
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: con->uri="/admin/?op=stop-printer&printer_name=a-1214-laser1", con->best=0x10515350(/admin)
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: level=CUPSD_AUTH_USER, type=Negotiate, satisfy=CUPSD_AUTH_SATISFY_ALL, num_names=2
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: auth=CUPSD_AUTH_ALLOW...
D [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: username="bse at CHALMERS.SE"
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: Checking user membership...
d [24/Jul/2008:10:23:00 +0200] pipe_command: command="/usr/lib/cups/cgi-bin/admin.cgi", options="?op=stop-printer&printer_name=a-1214-laser1"
E [24/Jul/2008:10:23:00 +0200] Unable to create new credentials cache (-1765328188/File exists)
d [24/Jul/2008:10:23:00 +0200] pipe_command: argv[0] = "/usr/lib/cups/cgi-bin/admin.cgi"
<snip>
d [24/Jul/2008:10:23:00 +0200] cupsdAuthorize: con->uri="/admin/", con->best=0x10515350(/admin)
d [24/Jul/2008:10:23:00 +0200] cupsdAuthorize: Authorization="Local 2E0E23C9F349FF7A1FA0F00E361C6EF9"
D [24/Jul/2008:10:23:00 +0200] cupsdAuthorize: Authorized as bse at CHALMERS.SE using Local
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: con->uri="/admin/", con->best=0x10515350(/admin)
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: level=CUPSD_AUTH_USER, type=Negotiate, satisfy=CUPSD_AUTH_SATISFY_ALL, num_names=2
d [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: auth=CUPSD_AUTH_ALLOW...
D [24/Jul/2008:10:23:00 +0200] cupsdIsAuthorized: username="bse at CHALMERS.SE"
E [24/Jul/2008:10:23:00 +0200] Authorized using Basic, expected Negotiate!
d [24/Jul/2008:10:23:00 +0200] cupsdReadClient: Unauthorized request for /admin/...
D [24/Jul/2008:10:23:00 +0200] cupsdSendError: 13 code=401 (Unauthorized)
D [24/Jul/2008:10:23:00 +0200] cupsdSendHeader: WWW-Authenticate: Negotiate

<snip>
d [24/Jul/2008:10:23:00 +0200] process_children()
d [24/Jul/2008:10:23:00 +0200] cupsdDeleteCert: removing certificate for pid 26631
D [24/Jul/2008:10:23:00 +0200] PID 26631 (/usr/lib/cups/cgi-bin/admin.cgi) exited with no errors.

Server: RHel5 latest update, Cups 1.3.8
Client: RHel4, late update, Firefox 1.5.0.12