ixfr-from-differences; journal not created on "rndc reload <zone>"

[Tim Maestas]

BIND-9.5.1-P1.

When "ixfr-from-differences yes;" is configured on a zone, and an edit
is made to the zone file and the zone reloaded via "rndc reload
foo.com" a journal file is not created.  However, when an "rndc
reload" of the whole configuration is done, then the journal is
created.  Is this expected behavior?  Why is the journal of the
differences not create on an explicit rndc reload of the zone?

Thanks.
-Tim