Can't log in to server with emacs-w3m

[Sean McAfee]

I've been a happy user of emacs-w3m for a few months.  Recently I tried
to use it to log into my company's internal issue-tracking server.  It
doesn't work, though; whichever page I try to visit, I get redirected to
the login page, and when I provide my username and password, I just get
bounced right back to the login page.

Does anyone have any ideas how I might get around this issue, or at
least start to figure out what the underlying problem is?

...I guess this is really more of a w3m issue than an emacs-w3m issue,
since I just ran w3m directly in a terminal window and encountered the
same problem, but perhaps someone here has already solved it.