[VPN] Slow Stunnel-PPP vpn through Openbsd nat firewall

[Peter W. Merritt]

Hello, I posted on the stunnel list and they suggested I post here.  I
have a stunnel pppd vpn setup between a openbsd 3.3 firewall and zaurus
pda. I can establish the connection on both ends of the vpn, ping hosts
on both my lan subnet and the internet. But using the internet through
the nat firewall is so slow that everything times out. I can see the
packets passing and returning through the firewall with tcpdump. I can
ping anything on the net, with normal ping times no problem. Its just
very  slow. I believe it has something to do with the natting because
speeds are normal browsing on the Lan hosts. Any help would be greatly
appreciated, I can provide any additional info needed, thanks in
advance. 
                             Peter