Javaupdatemanager.class (Downloader) trojan?

Hi.  I am running Norton Security Suite 4.2.0.12 on Vista Home Premium SP2, with two users set up, one with Admin rights.

 

 Every so often, Norton finds files that it labels as a High Security Threat in the Users\"username"\appdata\locallow\sun\java\deployment\cache\ folders.  Always an alphanumeric (hex?) filename like 2a5cd7-2d311244, and it says its a javaupdatemanager.class (Downloader).  It found one last night in the non-Admin account's \cache folder and quarantined it.  The odd thing is, the *exact* same filename exists in the cache folder on the user account with Admin rights.  So I had Norton scan it, and it showed it as clean!  I am confused, please help.  

 

Thanks

 

Jen