Integrated Security Problem? - User must log in repeatedly

[Michael E. O. Borchert]

I'm having a very isolated problem using with (I believe) windows integrated
security on a site on a corporate intranet, unfortunately the one person who
is running into the problem is the main person who needs to use the app.
When this one user (I have tried three others) clicks a "submit" button, the
server thinks for awhile (30-45 seconds), and then prompts her for her
username and password. Both fields are auto-filled, but the username has the
wrong domain. Hitting "OK" anyways causes the server to think for awhile
longer, and then returns an "Unauthorized request" page. Correcting the
domain causes it to think for awhile as well, and eventually prompt for
username and password again. This repeats about 2 or 3 times and takes about
5-10 minutes total, but eventually succeeds and it completes the submit. I
have tried from the user's computer myself (logged in as me), and had no
problems. When I (or other users) hit the same button, it returns in about a
second. The user has logged into windows using the correct domain. Does
anyone have any ideas about what might be going wrong?

[Mark Milley]

It's possible the browser has cached/stored the invalid password, and
it's trying to use that invalid password for each resource on the page
(including images, etc). Check the stored usernames and passwords. Also
check to see if you're securing items that you don't really need to
secure (images, etc)

-Mark