Despite Microsoft's promises to open up the Microsoft Network (MSN) to all browser users, some portions of that Web site are off-limits to users of the Opera and Amaya Web browsers.

The site in question, Carpoint, tells Amaya and Opera users that there are features on the site not compatible with their browsers and that they should upgrade to Internet Explorer:

Microsoft Carpoint that contains the latest new- and used-car features cannot be viewed using this browser. If you would like to see what you are missing......you can upgrade your browser to the latest version of Netscape, or click the icon below to download the latest version of Internet Explorer for free

The site works fine with the Netscape 4.7/6.2 and Mozilla 0.9.5 Web browsers across the Windows and Linux operating systems.

The blockage of Opera occurs when the browser is configured as Opera. When Opera is configured to appear as Internet Explorer or Netscape, Carpoint works correctly.

In a sharply worded press release, Opera officials accused Microsoft of purposely discriminating against Opera users.

"I hope now we will see a change where action matches the words and that Microsoft starts to actively supports the international standards, and starts working on getting their pages to work with other browsers instead of closing the door," says Jon S. von Tetzchner, CEO, Opera Software. "Microsoft has broken the Internet's golden rule that all Web sites should be accessible to all, no matter what browser or operating system they are using."

The ongoing controversy first surfaced last when Microsoft redesigned MSN in conjunction with the release of Windows XP. At that time several browsers, including Opera, Amaya, Netscape and Mozilla, would not load the MSN home page correctly, and users were told that they should switch to Internet Explorer.