Go to the
Spybot website & manually download & install the latest version of Spybot (currently v1.3, which was was released back in May).
As far as I've seen on other machines, v1.2 (which I assume you're still using) hasn't listed spware definition updates since v1.3 was released.
As of today the latest Spybot definition update is dated Aug 11 2004, but you'll only see it listed if you're using the latest version of the program.