I am running the Official Release of Windows 7 Beta build 7000 X64. I have done no "hacking" or "Tweaking" to date on this. Wanted to run it as intended and see how stable it was. I have been checking for updates daily and performing them as needed.
I experienced the same thing as described here today. Could not do any updates. Wouldn't even open that page.... So it wasn't any hacks or tweaks on my end, and it was with X64 for me, no x86. I did do the Send Feedback and also the Report an issue and described my problem. If anyone pays attention to those on MSofts end, then they got my info.
Hope this helps. I will try the fix described here when I have a moment and report back.