Windows 7 machines won’t sync time

I configured my Windows Server 2008 box as an authoritative time server using the instructions here: http://support.microsoft.com/kb/816042

Port 123 is open for incoming and outgoing connections on the server.

However, the other computers on the domain (which are all running Windows 7) will not sync time with it.

I get the following output from various w32tm commands (run on the Windows 7 machines):

C:\Windows\system33>w32tm /config /syncfromflags:domhier /update
The command completed successfully.

C:\Windows\system32>net stop w32time
The Windows Time service is stopping.
The Windows Time service was stopped successfully.

C:\Windows\system32>net start w32time
The Windows Time service is starting.
The Windows Time service was started successfully.

C:\Windows\system32>w32tm /query /source
Local CMOS Clock

C:\Windows\system32>w32tm /query /configuration
[Configuration]

EventLogFlags: 2 (Local)
AnnounceFlags: 10 (Local)
TimeJumpAuditOffset: 28800 (Local)
MinPollInterval: 10 (Local)
MaxPollInterval: 15 (Local)
MaxNegPhaseCorrection: 4294967295 (Local)
MaxPosPhaseCorrection: 4294967295 (Local)
MaxAllowedPhaseOffset: 300 (Local)

FrequencyCorrectRate: 4 (Local)
PollAdjustFactor: 5 (Local)
LargePhaseOffset: 50000000 (Local)
SpikeWatchPeriod: 900 (Local)
LocalClockDispersion: 10 (Local)
HoldPeriod: 5 (Local)
PhaseCorrectRate: 1 (Local)
UpdateInterval: 30000 (Local)


[TimeProviders]

NtpClient (Local)
DllName: C:\Windows\system32\w32time.dll (Local)
Enabled: 1 (Local)
InputProvider: 1 (Local)
CrossSiteSyncFlags: 2 (Local)
AllowNonstandardModeCombinations: 1 (Local)
ResolvePeerBackoffMinutes: 15 (Local)
ResolvePeerBackoffMaxTimes: 7 (Local)
CompatibilityFlags: 2147483648 (Local)
EventLogFlags: 1 (Local)
LargeSampleSkew: 3 (Local)
SpecialPollInterval: 3600 (Local)
Type: NT5DS (Local)

VMICTimeProvider (Local)
DllName: C:\Windows\System32\vmictimeprovider.dll (Local)
Enabled: 1 (Local)
InputProvider: 1 (Local)
NtpServer (Local)
DllName: C:\Windows\system32\w32time.dll (Local)
Enabled: 0 (Local)
InputProvider: 0 (Local)

C:\Windows\system32>w32tm /resync /rediscover
Sending resync command to local computer
The computer did not resync because no time data was available.

I also get the following error in my event log:

NtpClient was unable to set a domain peer to use as a time source because of discovery error. NtpClient will try again in 3473457 minutes and double the reattempt interval thereafter. The error was: The entry is not found. (0x800706E1)

How can I fix this?