Here's a funny one.

A directory of our Web site is requesting a basic authentication. This is Windows NT 4 SP3 IIS Option Pack 1. The user access the Web site and is prompted to enter his username and password. Once done, he sees the site. Now, we go in User Manager and give him a new password. He quits Netscape, start it again and enter the username and password. The new password works ok. He quits Netscape, start it again and enter the old password. The old password works ok as well. I went back on User Manager and give him a new password. The new password works ok as well as the other 2. Now, after doing more tests, he can now enter 6 passwords and all is working ok.

Is this a problem of IIS cache? I tried stopping and restarting it from IIS manager and it doesn't help. Is only a reboot will help?

This is just crazy.