NTP server - problem

[Kingfisher]

I have a system blue going (station 2241) and I notice that the time-stamp of NTP server
function is consistently 4 - 5 mS ahead of my other reference servers.  

Listed below is a time query from my workstation:-

allenc@pippin ~ $ ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+SHM(0)          .MSFa.           0 l   13   64  377    0.000    0.369   0.191
*SHM(1)          .DCF.            0 l   11   64  377    0.000    0.212   0.597
-blitzortung.cid .GPS.            1 u   61   64  377    0.721    4.834   0.136
+ xxxxxxxxxx .GPS.            1 u   40   64  377   33.641    0.141   0.101
+ xxxxxxxxxx  .MRS.            1 u   44   64  377   47.260   -0.848   0.657
+ xxxxxxxxxx  .GPS.            1 u  574 1024  377   33.485    0.484   0.204
- xxxxxxxxxx  xxxxxxxxxx     2 u   43   64  377   26.984   -0.006   0.435
- xxxxxxxxxx xxxxxxxxxx    2 u   47   64  377   27.614    0.175   0.236
- xxxxxxxxxx    xxxxxxxxxx   2 u   38   64  377   30.130    0.311   0.735
allenc@pippin ~ $
MOD EDIT:  REMOVED URL INFORMATION... please protect your security!
You can see that the time offset of every server except blitzortung is within + or - 1 mS. but  the
blitzortung offset is +4.8 mS

Obviously, you will want to keep the limited processing power of system blue available
for the primary purpose of monitoring lightning strikes,  but it would be nice if you
could get the NTP time-stamp a bit closer than 4 milliseconds.