The log actually tells that cron is alive and running. The problem can be into the script itself.
a. be sure the script is executable
b. check the root's mail (using the mail
command) to see if cron sent any standard error or standard output related to this job
c. redirect the standard output and the standard error to a file, at least during the test phase:
10,20,30,40,50 * * * * /root/auto.pl > /root/cron.log 2>&1
Anyway, what this script is supposed to do? What does it make you suspect that the script did not run properly (what is the expected result)?