The setup:
An exchange server 2003 backend, SBS 2003 front end, Outlook 2003 on
remote
client machines that connect via RPC over HTTP (cached mode).

The problem:
One user (and only one user) repeatedly gets a dialog window to
authenticate (DOMAIN/user, password) when Outlook is open and online.
He enters the information, clicks OK, and Outlook shows connected. Then

a few minutes later the same dialog box pops up.


Possibly relevant details:


* He uses basic authentication (as do all users)
* He enters his username/password each time (doesn't click "cancel"),
and is able to send/receive, so he is definitely authenticated at that
moment (i.e. not a bad password)
* He is usually using a wired internet connection (so it's unlikely his

connection is fading in and out)
* This does NOT happen on other computer systems set up identically and

using his username/password (albeit we tested this in non-cached mode,
rather than cached, because his mailbox is enormous). On other systems,

it shows connected and stays that way.
* There is no discernable pattern: sometimes he is typing an email,
sometimes he's opening one, sometimes he's in the calendar section, and

sometimes Outlook is just sitting in the background not being used at
all.


Any suggestions would be greatly appreciated. TIA!


JD