pfSense firewall not allowing TFTP requests out

I thought I’d post this in case anyone here has run into a similar situation and may have a clue. This is definitely a pfSense related issue.

Scenario:

RentPBX hosted FreePBX server is not receiving TFTP requests from phones located behind a pfSense firewall.

Another office is using a Cisco ASA, and has no problem getting requests sent to the server.

pfSense version 2.1.3-i386

Outbound rule to allow all traffic from LAN

Inbound rule allowing all traffic from RentPBX server

TFTP helper enabled on both LAN and WAN (have tried all combinations)

under System -> Advanced -> Network / Firewall -> Network Address
Translation -> TFTP Proxy you are going to select the respective interfaces on which the TFTP Proxy Helper shall be active.

Further more you might need to create additional rules to allow tftp traffic (port 69) from your LAN to the destination tftp server address located on the WAN.