Yay. Thanks to Susan for pointing this out.
Fixes the following issues:
• 917718 The ISA Server Control service may not start after you rename and then restart a computer that is running ISA Server 2004
• 917265 Error message when client computers that are behind a proxy server access Web sites that are published by using ISA Server 2004: “404 Not Found. The requested item could not be located (12028)”
• 917903 You cannot join a Windows Vista 64-bit client computer to a Windows domain on which ISA Server 2004 is configured as a firewall (Bingo – need this for my Ferrari x64)