crontab

I'm using Ubuntu 7.04. Will the scheduled commands in crontab run in the background even if i log out of my account?

*en.wikipedia.org/wiki/Crontab Can i use this to automatically download via Bittornado client. I tried using it for updating automatically at 2:00 am but it didn't work. Just didnt start. This is what "crontab -l" said: 0 2 * * * aptitude -y update && aptitude -y upgrade && aptitude -y...