I have an SBS 2003 server that I'm trying to apply the Vista/Office 2007 update to (KB 926505). This errors with "This update cannot be installed. Either it is already installed as part of an existing service pack, or it requires a more recent service pack."
It turns out Server 2003 SP2 was applied to this machine without first installing the superseding SP1. Is it safe to apply the last part of the SBS SP1 update (specifically SBS2003-KB885918-SP1-X86-ENU.EXE) over the top of SP2?