If receiving 800B0001 errors on domain connected machines on your SBS 2008 network, it's because an update had strengthened the communication channel between the machine and the SBS server and broken the connection.
Ignoring the absurdity of the issue, the fix is to run an update on the SBS box. This page talks about it (you can ignore the portions about NLB - network load balancing for your SBS box):
http://support.microsoft.com/default.aspx?scid=kb;en-us;2720211
In essence, the resolution is to download this:
http://www.microsoft.com/downloads/details.aspx?FamilyId=2ba0b137-d85b-4734-9a95-11a04004a355
and run this command from an elevated command prompt:
WSUS-KB2720211-x64.exe /q C:\MySetup.log