When SpecialPollInterval is used as a polling interval, Windows Time service does not correct its time if it gets into Spike state.
On a NTP client computer that is running Windows Vista, Windows Server 2008, Windows 7 or Windows Server 2008 R2, it may not correct its time if the following conditions are true:
- The NTP client syncs its time with the manually specified NTP server.
- The NTP client uses SpecialPollInterval as a polling interval.
- The time offset between the NTP client and the NTP server is greater than the LargePhaseOffset configured in the NTP client.
In this situation, the NTP client cannot correct its time even after waiting for SpikeWatchPeriod is over.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB2638243.