I also noticed my cron tasks were running off time also. Hardware time and software time were all correct however, quite the mystery. Today I installed and set up NTP daemon and did an upgrade to beta 6, the issue seems to be resolved now.I looked at the forum on the day this came up, but it's effectively impossible to see if there's an issue from the outside. Do you still see this happening?
Are you sure the server time is correct? And I mean not only is the time correct, but it has to be in the correct time zone for that time.