I'm familiar with the settings and features at: webmin > hardware > system time > time server sync
on our Ubuntu 14.04 LTS server running webmin/virtualmin.
At one point, I put the wrong hostname for an ntp server -- and no matter how I try, I cannot change any settings on the "Time Server Sync" tab on the "System Time" page and have them save. They appear to save, but when I go back and look at them -- they haven't change. I've tried rebooting the server (out of futility).
Where are these settings stored? Can I delete or edit them directly?