Starting clamav-milter: /usr/sbin/clamav-milter: --timeout must not be given if --external is not given [FAILED]
I had the same error with clamav upgrade on FC4.Edit "/etc/sysconfig/clamav-milter" and insert "--timeout=0" as one of your CLAMAV_FLAGS.
The clamav-milter man page states the "timeout" default is zero, but it didn't seem to work.
HTH Miles.