>Turning off RFC1323 options fixes the problem.  This is an easy enough
>fix, but I'm curious as to what's going on.  My best guess is that the
>timestamp calculation is trying to do some network pacing, and is doing
>a really bad job of it.

Well, turns out I should have waited to send this out.  I was talking with
a friend about this problem, and he said, "Did you try turning off VJ
header compression?"  Turns out the Netblazer that I use for my PPP 
access likes to eat some packets if VJ header compression and IP options
are turned on.

So if anyone else runs into the same problems, my advice is to turn off
VJ header compression and see if that helps.

--Ken