This was an update I received recently. It would "seem" to bear out problems you may be having. This is why I prefer Linux. MS is in the money business and just too intrusive. Hope it helps somehow.
Update for Windows Vista for x64-based Systems (KB955430)
Installation date: 6/9/2010 11:48 PM
Installation status: Successful
Update type: Important
Install this update to enable future updates to install successfully on all editions of Windows Vista. This update may be required before selected future updates can be installed. After you install this item, it cannot be removed. This update is provided to you and licensed under the Windows Vista License Terms.
More information: http://support.microsoft.com/kb/955430
Help and Support: http://support.microsoft.com
“I am enough of the artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.” Albert Einstein