For what it's worth, I run ssh with forced-command keys from cron
jobs.  However, rather than having the ssh command itself in crontab,
a script is invoked from crontab and that script then executes ssh
(among other commands).  A relevant line from one of these scripts is:

  ssh -2 -q -n -i /home/foo/.ssh/bar some.host.net >> $OUTFILE 2>&1


Bill Chiarchiaro
wjc@cleartech.com