I'm keeping tabs on a remote sever that is running Symantec AntiVirus Corporate Server 10.1.7.7001. About a month ago, the Virus Definition File version date stopped updating and hasn't updated since - 3/26/2012 rev. 2. The automatic update has continued to run everyday, downloading the latest definitions, but not updating the version date in the client.
I have run the LiveUpdate service manually. Sometimes it downloads an update successfully and other times it says the virus definitions are up to date. If I run it again after a successful download, it will always say it's up to date. I don't think it is an issue of getting the virus definition.