Port forward or Routing issue

I have a range of IP addresses from our ISP (ex: 10.10.10.0/28) (using this subnet as an example only, they are routeable IPs)

10.10.10.1 is my ISP’s gateway

I have a Mikrotik router on 10.10.10.2/28 WAN side, doing src-nat masquerade for the internal LAN at 10.171.XXX.XXX/20

I have several VOIP devices or linux boxes on 10.10.10.3-10.10.10.8

From ANY remote location I can browse to these direct connected devices, connect to them, etc. HOWEVER, from any internal IP (10.171.XXX.XXX) I cannot browse to port 80 (http) on any of the devices outside the router. I can however ping their IP from inside the LAN, and a tracert is successful also.

Any ideas??

http://forum.mikrotik.com/t/port-forward-or-routing-issue/48621/1