We have released a fix tool for the “Virus & Spyware Definitions are not up-to-date” alert when LiveUpdate shows that you have the latest protection updates that some of your have experienced with Norton 360. The Fix Tool is available in the following Knowledge Base article:
Norton 360 alerts that your virus & spyware definitions are not up-to-date, and running LiveUpdate shows that you have the latest protection updates
http://www.symantec.com/norton/support/kb/web_view.jsp?wv_type=public_web&docurl=20090319152047EN
Thank you for your patience while we developed and tested this fix tool.