Machines not checkin in at the set frequency

[DeployAdam]

We have set the Recurring Check-in Frequency to every 15 minutes but almost every machine we have is not checking in every 15 minutes. As far as I can see now some machines check in when a user logs in on a machine.

We have a energy saving policy which is set to boot the machine at 11 o clock in the evening and shutdown at 5 o clock in the morning. Initial we'd like to use this as a maintenance window to let policies run when machines ar booted. But while machines will boot they won't check in to see which policies are available to execute.

Anyone who has a suggestion to point us into the right direction?

[tnielsen]

How recently did you change that setting? Keep in mind that it's the clients that check into the server, not the server that tells the clients to check in. Therefor there will be no uniformity on timing, which is a good thing.