cron changes after the update, again

I have in crontab a job that is scheduled every half an hour, in this way:
10/30 6-19 * * 1-5  sync.sh
that was there since the installation of this server, a couple of years ago.
That means it run at 10 and at 40 of every hour between 6 and 19, monday to
friday.

Now after the last cron update it's not working anymore, gives this error:
crontab: installing new crontab
"/tmp/crontab.XXXXMceiAS":13: bad minute
(line 13 is the crontab line above)

it's not the use of '/', since in the same crontab i have another job that
is scheduled in this way:
1-59/3 6-19 * * *  check.sh
and this one is working without errors.
More on this, if i put "*/30" it's working good.
But i need this job to start 10min past hour change, so i need the "10/30".

funny thing is, the job was working at time scheduled even after the update,
only it won't let me change the crontab.

Any advice is welcome.
Gio.

--
Taroon-list mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/taroon-list