> I have NetBSD running on the ASUS-SP3G and over one year the clock has 
> become 15min late...  anyone have this problem or know how to fix it?

Congratulations, your clock crystal is accurate to within 28 parts per million.
That's pretty darned good!  (Nominal is around 100ppm.)  My system gains about 
1 minute per *day*.  I'm currently using xntp to keep it in line, although my
clock has enough short-term variability that it violates the xntp assumptions
(thus xntp regularly winds up jerking the logical clock around by a second or
so).

Or, you can remember to set your system from your watch every month.  That's
assuming that your watch is as good as 28ppm!