journal files in bind9

[Jeff]

BIND 9.2 DDNS and journal (<db-file>.jnl) file update question:

When 'rndc stop' is issued, and dbfile.jnl entries are flushed to the actual
dbfile, what happens to the jnl file? ... are the entries that were just
flushed still in the *.jnl? or are they removed? ... if the newly flushed
entries remain in the jnl, how does named know not to overwrite the dbfile
next flush (after named is started back up of course)? serial number entries
in the jnl file? other?

I am trouble-shooting an odd problem where my DB files arent always updated
with an 'rndc stop' and am wondering if leaving the journal files in place,
even after an rndc stop, is ok.  Or removing them (as we always do) is
adding to the problem ... I know most people remove them for good house
keeping, but I could find nothing on the web documented saying that it was
NOT okay to leave them in place ... my sysadmin is under the impression that
you "must" remove them ... i dont know where he got this idea and was trying
to figure out a definitive (documented) answer ..