Problems emerged on 25 October, when Microsoft upgraded its MSN.com site in a way that left many non-Microsoft Web browsers unable to view the site. Users unable to access the site were told their Web browser was unsuitable and were offered the chance to download Microsoft's own browser instead.
The company admitted that some browsers were unable to display the site because they did not support Extensible Hypertext Markup Language (XHTML), a standard for rendering Web pages. Users complained that Microsoft had classified their non-IE browsers as "unknown". This classification is typically reserved for old browsers that are known not to work on MSN.com, Microsoft claimed.
Among the browsers unable to access the site were Opera, Mozilla and HotJava.
Microsoft announced on 29 October that it had tested the new MSN.com site against "the most popular browsers on the market". The site should now be accessible to all users, said Bob Visse, MSN's marketing director.
However, attempts made on 29 October to access MSN.com using a HotJava browser returned an error message.
A Microsoft spokeswoman claimed she had not heard about a continuing issue with HotJava.