Technical,
I don't know if this applies to your situation, but I thought I throw my 42 cents worth in.

I too had noticed that
SB S&D had not found any updates in quite some time. I thought it strange since I'd heard about a few new threats that I felt certain would be promptly addressed. I had used the program to check for updates numerous times over the course of a month or so, but it always indicated that none were available.
After reading this thread Wednesday, I tried again to get
SB S&D to update itself, but it reported that no new updates were available. I checked the web site and discovered that 2 or 3 updates had been released since the last one I'd obtained. I also checked some other resources and discovered other complaints, with overloaded servers being blamed most of the time. I tried to get them repeatedly, from each of the mirrors, without success over the next serveral hours.
Then I had my idea for the week. I log on to my system, which runs
Windows XP Home Edition, using a limited account about 90% of the time. About the only time I use an adminstrator account is when I want to check for and install Windows updates, install software, or update existing programs.
Last night I decided to try to get the updates while logged on under an administrator account. I started
SB S&D and had it check for updates. This time it quickly found, downloaded, and installed them without a hiccup. In the past I know I've checked for updates as a restricted user, with the intention of making a mental note to download and install them later as an administrator. I can't say for sure, but at this point I'm willing to believe that
SB S&D has never found any updates when I wasn't logged on with administrative rights.
Regards,
Hornus