WSUS and Windows Vista SP1
Windows Vista service pack 1 is due "any time now". Various on-line blogs and articles are saying anywhere from February 1 to February 15, although Microsoft could wait all the way until the end of March and still meet their "Q1 2008" official time-line.
Vista will be released via Microsoft Update, WSUS, and System Center Essentials. However, there is a problem... Windows Server 2003 sp1 and Windows Server 2003 sp2 cannot verify the electronic signature on files as large as the service pack! Once you approve the update, you will download the service pack, verification will fail, and you'll download it again... not a loop you want to get into with WSUS.
There is a hotfix. This falls into the "get it, install it, don't forget it" category.
The hotfix is KB 938759, "You cannot distribute or install a software package in Windows Server 2003 if the software package contains a very large signed file".
This is from the System Center Essentials Team Blog.