Sure hope you get an answer. I have the same problem.
I wound up on v5 after installing and then uninstalling sp2 beta. Now I can't install the latest security update KB867801 as it leaves me without a desktop.
I went to Windows Update page and it says V5. I don't like the way it works. Is there any way to go back to V4? I don't remeber installing V5. It also changed my Automatic Updates setup in XP. Again I don't like it. I sure would like to get rid of it.