the latest version, which as Mark says is 5.0.1144. I am surprised when you check for defs updates, that the program does not tell you there is a program update, The version you have is from December of 2010. There have been over a dozen program updates since then. It is probably no longer supported. Because you are so many versions behind, I would recommend uninstalling it and then install the newest version.
The free version is the donwload on the bottom of this page.
http://www.superantispyware.com/download.html
Is there something going on with SAS re their definitions? I used to download them regularly at least once a week, but the last update I was able to get was dated 02/16/2012 core 8206 trace 6018. My ver is 4.47.1000, When I try to update, I am told the definition database is up-to-date. In addition to SAS, I have Malwarebytes Anti-Malware free and NIS 2012.
My thanks....Miki

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic