Freshclam problems

[Anne Wilson]

On my server, running CentOS 6, I've started getting messages like

 No updates detected in the log for the freshclam daemon (the
 ClamAV update process).  If the freshclam daemon is not running,
 you may need to restart it.  Other options:
 etc...

and

/etc/cron.daily/freshclam:

ERROR: Problem with internal logger (UpdateLogFile = 
/var/log/clamav/freshclam.log).
ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check 
permissions!).

This began after an update, and I've changed nothing in the configs.  Freshclam 
ran without problems before the update, but I'm struggling to sort this out.

First, then, can you tell me what permissions freshclam.log should have?  
Currently it is owned clamav:clamav with rw access for clamav.  I read that 
freshclam is launched by root, but then drops to an unprivileged user - is 
clamav that user?

What other checks should I be making?

Anne