The best that I can offer is a link to help information for this error:
http://help.live.com/help.aspx?project=onecarev2_5_client&market=en-us&querytype=topic&query=onecare_trou_error_80048869.htmThere is something about your LiveID account or environment that is causing your issue if it is happening consistently with multiple PCs after clean installs of the operating system and different LiveIDs and subscriptions to OneCare.
It is not a common problem, being reported here in the forums only rarely in the years since OneCare was first released. It is a login issue of some sort, possibly credentials releated.
Personally, as long as all else is working in OneCare, I'd give up on trying to resolve the error when trying to make the PC a hub PC. There really isn't much advantage to the OneCare Circle to spend hours troubleshooting it. Also, be sure to check out the announcement at the top of the General topic folder. OneCare is going away.
If you have any case numbers for your support contacts and can post them here, I'll forward them to Microsoft for investigation as it sounds like your support experience was pretty bad.
-steve
Microsoft MVP Windows Live / Windows Live OneCare & Live Mesh Forum Moderator