It's up to Spybot 2.4 now,if you wish to update.
http://www.safer-networking.org/dl/
My Firefox usually immunizes very slowly,especially somewhere in between when Images and Installations are being immunized,to the point where it appears to be stuck.To see if you might be having the same thing happening,try opening Spybot Start Center,click Immunization,after the immunization check is done,click Show Details,somewhere within the Immunization window,rightclick and select Deselect All.Next,under your Administrator entries in Firefox,checkmark (Cookies) only,then click Apply Immunization.Let me know if just the cookies immunized or not.