> Replacing msntp with ntpd and associated tools bloats it up to 10050k,
 > 400kb more.

Deja vu all over again ...

If I remember correctly, when I looked at this back when I did the 
initial msntp integration for m0n0wall (which I hasten to add was 
reworked substantially by Manuel and itself derived heavily from 
comments and help from people like Fred), it was a relatively simple fix 
to msntp to make this work correctly with XP. I suggest going that route 
before messing with ntpd.

Run msntp in server mode and turn the debug up all the way and it 
quickly becomes apparent what's wrong with XP (reports as being a server 
instead of a client or somesuch). Then grep the source and hack it with 
a special case if() test. In brief correspondence with the msntp author 
he concurred that this would work, but declined to hack his source to 
fix an XP problem.  I didn't have a build environment setup and never 
got around to it.

Of course by now, two service packs later, XP may no longer have this 
problem...  Wouldn't take long to find out. Just exec.php and start 
msntp as a server, point XP at it and see what happens...

Good luck!

cheers, michael