I'm (still) running NetBSD 1.4.2 on a SPARCstation 20.

I keep having problems with clock skew, despite the fact that I have 3
NTP chimers in ntp.conf - time.Apple.COM and 2 machines at my work -
and time seems to be set OK at boot time and "xntpd" keeps humming along
as far as I can tell, and when I occasionally run "tcpdump" to look at
something, I see NTP traffic.

Example - I look up at my Mac's clock, it says "4:15 PM".  Sun says "4:13":

[16:13] isolar:~/Mail/inbox % ps -ax | grep ntp
  319 ??  S<s    3:39.26 xntpd -p /var/run/xntpd.pid -f /var/db/ntp.drift
[16:14] isolar:~/Mail/inbox % sudo kill -HUP 319
Sep 18 16:14:12 isolar xntpd[319]: xntpd exiting on signal 1
[16:14] isolar:~/Mail/inbox % ls -l /var/db/ntp.drift
-rw-r--r--  1 root  wheel  6 Sep 18 15:24 /var/db/ntp.drift
[16:14] isolar:~/Mail/inbox % hexdump !$
hexdump /var/db/ntp.drift
0000000 302e 3030 300a
0000006
[16:14] isolar:~/Mail/inbox % sudo ntpdate -b -s <work NTP host 1> time.apple.com <work NTP host 2>
Sep 18 16:16:29 isolar ntpdate[13900]: step time server 17.254.0.31 offset 92.076963 sec

The version # is:

isolar# xntpd -p /var/run/xntpd.pid -f /var/db/ntp.drift
isolar# Sep 18 16:17:28 isolar xntpd[13911]: 5.93c 3-NetBSD Wed Aug 12 10:05:25 EDT 1998 (1)
Sep 18 16:17:28 isolar xntpd[13911]: tickadj = 40, tick = 10000, tvu_maxslew = 3960, est. hz = 100

Anyone know why my SPARCstation clock was off by over a minute and a half?!?
I don't get it.  Is this a NetBSD problem with "adjtime", or is my SPARCstation
just getting slow in its old age?  <*scratches head*>

	- Greg