The problem occurs in Internet Explorer 4.0 browsers that are linked through Microsoft Proxy Server 2.0 to Microsoft Internet Information Server (IIS) 4.0. When trying to refresh pages that contain Java or Active Server Page (ASP) scripts, images may be lost and fail to download, according to Microsoft.
Microsoft's technical support site has suggested downgrading to IE 3.0 or IIS 3.0 as a temporary solution.
Normally, IIS 4.0 sends information back to the browser, where part of the information is displayed as the body of the page and another part is sent to the header where it provides the browser information about how to render the page.
But Microsoft attributed the problem to a missing header when the IIS 4.0 sends information to the IE browser. That means the bug disrupts the information that tells the IE browser how long the content will be, and causes the browser to hang in anticipation.
Kratofil said he guessed that pages with active content somehow block information that provides the content length to the browser. As a result, the browser does not know when to stop waiting for content, thus causing the page to hang.
Microsoft representatives declined to comment.
Microsoft is currently testing a fix for the problem, which it will release in its next Service Pack, the company stated on its Web site.