title: IE, FireFox, Opera, and Safari don't display BASIC auth prompt on successive 401 responses from server
body: <p>SCENARIO:</p>
  
  <p>I have a java web app running in the latest Tomcat 6.  I also have a single servlet filter that provides authentication.  I support BASIC auth and it appears to work fine - most of the time.  </p>
  
  <p>The first time a browser [pick any one - IE, FireFox, Opera, Safari, Chrome] hits one of our protected URL(s), it displays the standard browser-specific login prompt.  IFF you enter the proper username/password - everything is fine, a new session is created, and everything operates normally.</p>
  
  <p>IF, however, you entered invalid credentials in the initial BASIC auth dialog, my authentication filter logic handles this by returning another 401 response.</p>
  
  <p>PROBLEM:
  Unfortunately, at this point, Chrome is the only browser that will display another BASIC auth dialog.  All other browsers listed automatically send the cached "Authorization: Basic.." header - instead of clearing it and prompting the user again.</p>
  
  <p>If anyone has seen this or may know why this is happening, I would greatly appreciate any suggestions!</p>
  
  <p>Thanks and Best Regards,
  Bob</p>