We have a new version which is currently in beta testing that supports SP2. If you'd like to try the beta (which also has an HTTP scanner, among other things), you can get it here: http://www.nod32.com/download/downbeta.htm

Kirk
I wrote an inquiry to the makers of NOD32 about the lack of support for the security center of SP2 in windows XP. The above is the response I got.