All the cron entries my 4.0 Suns had between (not sure) either 2:00 AM or 2:01 AM and 2:59 AM or 3:00 AM failed to function from April 2, the "spring forward" night, until the next time I did a "crontab -e." So there must be a bug in cron, and system administrator's should be aware that some processes might not be running.