According to Trimble ( http://www.trimble.com/y2kwnro/pdf/sv6pre5_04.pdf ):

The products that contain firmware versions prior to 5.04:
1. Will not report the correct calendar date after the Week Number Rollover
event occurring on August 21/22, 1999.  The TAIP TM message and the NMEA
messages RMC and ZDA contain a calendar date field. The date reported in these
messages is calculated from the GPS week number as transmitted by the GPS
satellites. When the GPS week rolls back to zero, the date reported in these
messages will be incorrect. Position reports will be correct.
2. Will not report the correct time of day in the TAIP TM message for the first
55 days following the Week Number Rollover event occurring on August 21/22,
1999. Correct time of day reporting will resume after October 16, 1999. Position
reports will be correct. The TAIP CP, LN, and PV messages WILL report the
correct time (based on GPS time) after the Rollover event.

Now, it is not said whether it is a simple fix of taking the date given and
adding 1023 weeks to get the correct date, but I imagine that's the case.  I'm
not sure how the time is being messed up, but it is only wrong through October,
at which point it will be correct for another 1023 weeks.

Position reporting (the main reason for having a GPS, right?) will not be
affected except that the unit will take 15 minutes to get it's position the
first time it is turned on after the week roll over.  After that one time it
will take the normal amount of time as it did before.

So if anyone bought the gps receiver from BGMicro and wants to sell it because
the date and time will be wrong, or require adjustment, I'll buy one from you
(Set it up at home as a reference so I can get a little more accuracy...  Not a
full blown dgps, though)

-Adam

Tjaart van der Walt wrote:
>
> Are you guys aware that all CM3 receivers with firmware older
> than 5.04 will puke out the wrong date after August 21 this
> year?
>
> It is called the "GPS week ollover (WRO)". The effect is
> similar to Y2K in that the weeks were counted from 1980, and
> in August it will reach 1024.
>
> If you think flying on December 31 will be unsafe, try August 21/22!
>
> Get more info at :
> http://www.wasp.co.za/~tjaart/gps.html