Recurrent /var/webmin/modules/package-updates Activity after 1.770 Upgrade

Since upgrading Webmin to 1.770 (CentOS 6.7 on Amazon EC2), I am seeing activity in /var/webmin/modules/package-updates every five minutes. The time and inode of current.cache changes but the contents does not appear to be modified. I have verified that Software Packages Update is still set for 'weekly'. So far I have not found any logs that explain what is happening.

Is anyone else seeing this? As far as I can tell, this five-minute activity isn't causing any impact - I would not have noticed anything if I were not running a file access monitor.

Thanks, Norbert