ntp problem

[Pierre Frenkiel <pierre.frenkiel@gmail.com>]

hi eveybody,
I recently discovered that the time on my desktop was wrong by several minutes,
although it is running ntpd. On my laptop, which has exactly the same ntp.conf,
the time correct.
Here are the output of ntptime on the 2 machines
laptop:
   ntp_gettime() returns code 0 (OK)
     time d753a7ab.725bfaa8  Tue, Jun 24 2014  9:30:51.446, (.446716067),
     maximum error 188962 us, estimated error 4294 us, TAI offset 0
   ntp_adjtime() returns code 0 (OK)
     modes 0x0 (),
     offset 270.965 us, frequency 1.879 ppm, interval 1 s,
     maximum error 188962 us, estimated error 4294 us,
     status 0x2001 (PLL,NANO),
     time constant 7, precision 0.001 us, tolerance 500 ppm,

dektop
   ntp_gettime() returns code 5 (ERROR)
     time d753a7d7.19c92000  Tue, Jun 24 2014  9:31:35.100, (.100725),
     maximum error 16000000 us, estimated error 16000000 us, TAI offset 0
   ntp_adjtime() returns code 5 (ERROR)
     modes 0x0 (),
     offset 0.000 us, frequency -500.000 ppm, interval 1 s,
     maximum error 16000000 us, estimated error 16000000 us,
     status 0x41 (PLL,UNSYNC),
     time constant 7, precision 1.000 us, tolerance 500 ppm,

I tried ntpdate, which actually restablished the correct time, but 30
minutes later, the time has already drifted by 15 seconds.

Any possible explanation?

best regards,
--
Pierre Frenkiel