CheckPoint firewall not passing gpxe dhcp etc requests via dhcp relay mechanism

Issue

• We are having an issue with our firewall in that they are not passing the initial RHEV Virtual Machine gpxe dhcp request onto our dhcp server located on another subnet. Basic configuration is that we have two subnets separated via a firewall. The RHEV Hypervisor (FULL Linux install) is installed on subnet 1. We have a DHCP Helper configured on the firewall to pass DHCP requests to our DHCP server located on subnet 2.
• The gpxe dhcp request is not liked by the firewall and being dropped however we can see no obvious reason why as the "standard" dhcp requests (generated by RHEL) are getting through which suggests the firewall rules are correct as gpxe is just another pxe isn't it ?