Microsoft have released a couple updates on the Microsoft Download Center to resolve various issues in Windows Vista:
-KB943899 (x86) (x64): This is a reliability update. This update resolves some performance and reliability issues in Windows Vista.
-KB943302 (x86) (x64): Install this update to resolve a set of known application compatibility issues with Windows Vista.
Both updates are marked as preview releases. At the conclusion of this preview phase, the final version of the updates will be released via Windows Update. These updates are provided to you and licensed under the Windows Vista License Terms.
Windows Vista, Security Update, WSUS, Windows Update, Microsoft