Author: M.Prince (18 Aug 09 9:00pm)
The http:BL database does not always exactly match what is online. We update the http:BL database as quickly as possible. The website is updated less frequently. Both systems are complicated further by caching. The website pages are cached which can cause them to be updated less frequently. Http:BL gets cached by your local DNS servers which can also cause different results to appear if an update occurs after the caching.
While these are all explanations, I'm not sure that explains your situation. Typically if there's a difference then the last active date would be <1. Might you be looking at the wrong octets within the returned code? Might be worth experimenting with some other IPs and see what results you get.