Error message when you try to access a Web site that is published through ISA Server 2004 SP2: "HTTP 400 - Bad Request" or "Error Code: 500 Internal Server Error"

When you try to access a Web site that is published through Microsoft Internet Security and Acceleration (ISA) Server 2004 Service Pack 2 (SP2), you receive one of the following error messages:Note Sometimes you may not receive an error message. However, the Web site or the Web program that you access may still not work correctly.

This problem occurs because ISA Server 2004 SP2 adds an additional space between some headers and their values. For example, the following header information may be sent by an ISA Server 2004 SP2 computer to the Web server:When this behavior occurs in the host header, some Web servers incorrectly interpret this as a cookie name that starts with a :space. This causes some Web servers that are published through ISA Server 2004 SP2 to work incorrectly.

To resolve this problem, obtain the Update Rollup for ISA Server 2004 SP2. For more information about the Update Rollup for ISA Server 2004 SP2, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.