A little helpful information
I had similar although minor problems as the others here.
When running update from the start centre I would get messages about files that could not be downloaded.
My solution was to go to C:\Program Files (x86)\Spybot - Search & Destroy 2 and right click SDUpdate.exe and run it as administrator.
This fixed my problems as the files were then downloaded from a completely different location.
Although I did have to click the update button a couple of times to get it to work
Hope this helps
cheers