ClamAV 0.94 and older end of life and disabled on 2010-04-15

http://www.clamav.net/lang/en/2009/10/05/eol-clamav-094/

ClamAV has released an announcement that versions older than 0.95 will
be disabled after 2010-04-15.

ClamAV would like to release longer malware signatures that aren't
supported by pre-0.95 versions of ClamAV. For this reason, earlier
versions of ClamAV will break when new signatures are released.

ClamAV has sent out a special update that will disable ClamAV
installations older than 0.95. This means that your installation may
not be working as of today.

If you are using pre-0.94, you should upgrade immediately to avoid
possible incoming malware. 0.96 is available and should be used.

Thanks,
Brian