user cronjobs are not performed

[Simon Zilliken]

Hi,

I just set up a user crontab for a daily virus scan, but the job is not done. 
Looking in /var/log/syslog I found the line

Apr 13 11:25:01 localhost /USR/SBIN/CRON[4897]: (simon) CMD (nice clamscan 
-rl /home/$USER/Desktop/clamscan.daily /home >& /dev/null)

so it looks like cron has started the job ... but it doesn't do anything, and 
I there's no process with PID 4897.
The clamscan command is alright, I've checked that. I don't know what I could 
have forgotten. Can someone give me a hint?

Thanks,

Simon