crontab and users?

[David Bellows <bfootdav@bellsouth.net>]

Hello all,

I'm having problems getting cron to work as a user.  I'm trying to get
the progam jac (a command line CD player that does work, btw) to run at
specific times to act as an alarm clock.  As a user here is my crontab:

38 17 * * * /usr/local/bin/jac -P1
 
Which should mean that it will play at 5:38 PM.

This same crontab installed by root works!  Is there some kind of
permission thing to allow users to use cron?

Btw, is there a user that I can specify in cron that will work without
being logged in (in case power goes out and I don't wake up and log back
in)?

Thanks,
David Bellows