IE and cached passwords

[JKing () GFPGROUP COM (Justin King)]

In Internet Explorer (v5/nt,v4/nt,v5/win98), when I go to a website (say,
www.company.com), and it requests authorization (via basic authentication),
and I enter it, I am able to browse the rest of the site without reentering
my password on each page. This is fine. However, if I go to another website
on the same machine, but a different port (say, www.company.com:81), my
authentication information is still sent.

This seem to me to be a security flaw with the browser. The potential for
abuse doesn't really seem very high, but I do think it's there.