[CentOS] IE 9 not sending digest auth info

I migrated our internal wiki server last week, and some IE users 
aren't able to authenticate.

The service is hosted by Apache using Digest authentication. It 
migrated from Apache 2.2.9 (Debian 5) to Apache 2.2.15 (CentOS 6). The 
internal hostname for the wiki server is a DNS CNAME that was 
repointed from one host to another during the cutover.

In a normal session,

1. Client sends GET
2. Server sends 401 with WWW-Authenticate header
3. Client sends GET with Authorization header
4. Server sends 200 with Authentication-Info header and page content

When using IE 9 (and possibly 8, I'm still trying to track that down),

1. Client sends GET
2. Server sends 401 with WWW-Authenticate header
3. Client resends GET (*without* Authorization header)
4. Server sends 401 with WWW-Authenticate header
5. Etc.

IE seems to be ignoring 401 and/or the WWW-Authenticate headers. Using 
Chrome on Windows works fine; the issues are specific to IE.

Any ideas? My google-fu has failed me.

-- 
Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/