Canceling multiple file downloads on a large file causes Internet Explorer to stop responding

If a Web server uses the "Content-disposition: attachment" HTTP header to force a file download, and the user cancels the download 2 or 4 times from the Save As dialog box, Internet Explorer appears to stop responding ("hang") during the next attempt to download the file. The download indicator in the upper-right corner of the browser continues to advance for 15 minutes before the browser renavigates to an error page that indicates that the download was unsuccessful. After this, Internet Explorer will not respond to any attempt to access that Web site.

This problem occurs consistently only with large files or slow connections.

In this specific scenario, Internet Explorer strands a connection to the Web server. This connection won't be reused or closed until Internet Explorer is closed. Because of the HTTP-enforced, per-server connection limit, after 2 or 4 connections are stranded, Internet Explorer is no longer able to create new connections to the server and will time out waiting for one of the stranded connections to close.

To resolve this problem, obtain the latest service pack for Internet Explorer version 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in Internet Explorer 5.5. This problem was first corrected in Internet Explorer version 5.5 Service Pack 1.

Steps to Reproduce Behavior

1. Open a fresh browser instance.
2. Visit a large resource on a Web server that uses the content-disposition header to force the File Download dialog box.
3. When the File Download dialog box appears, click to Save the file, and then click OK.
4. When the Save As dialog box appears, click CANCEL to cancel the download.
5. Repeat steps 2 through 4. This may take 2 or 4 repetitions on some computers. Eventually, Internet Explorer will hit the connection limit and time out on any request to that server.

NOTE: For the behavior to occur, the user must cancel the download from the Save As dialog box. The problem does not occur when the user cancels the download from the first File Download open/save dialog box.

For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
For more information about developing Web-based solutions for Microsoft Internet Explorer, visit the following Microsoft Web sites:
http://msdn.microsoft.com/ie/