I am having problems with randomly occurring HTTP_403 messages trying
to get my Pocket PC and smartphone to sync to my exchange 2003SP1
server.  I have a Dell Axim x50v pocket PC which can sync through my
smartphone's GPRS connection as well as wirelessly.  When I am syncing
through GPRS, I go through an OpenBSD NAT'ing firewall that redirects
443 traffic to my exchange mailbox.  When syncing wirelessly, I am
connected to an access point on the same subnet.  Syncing works about
30% of the time, while other times resulting in an HTTP_403 error.
This error occurs both with wireless sync and GPRS sync.  What the two
sync methods have in common is that I'm rerouting all https requests
from my private subnet through the OpenBSD firewall, which hands it
back to my exchange server.  My reasoning for this is that I can now
access my public sites from the internal net without using a split DNS.

I have installed the certificate on both devices, and have turned off
SSL on my newly created exchange vdir.  I cannot seem to be able to
reproduce this in a predictable fashion and was hoping for some insight
into what I could look into next.  

Thanks,

Mattias