Multicast on Checkpoint

Hello,

The setup is the fallowing a Cisco 6500-firewall cluster-Cisco 7200. The problem comes when I try to make the joint to a multicast group the firewall block it.  The approach to resolve this came from the network technician and the solution was to create a GRE Tunnel between the two Cisco, this work well for some time, but the problem is we are starting to use some great collaborative applications that require 30MG of bandwidth incoming and outgoing simultaneous so there will be 60MG of traffic per conference.  The problem is that the process that the Cisco have to make to put this packet on the GRE Tunnel elevates the CPU on both Cisco to the point that the Cisco start to deny service to other application. A brute force solution is to change the supervisor on the Cisco 6500, we try this on Cisco labs and it work the CPU still go up but not to the point to deny service.

What I am looking is ways to configure the checkpoint to permit the multicast traffic go throw it. I am not a firewall expert but if some one can point me in the correct directions I will appreciate it.

Thanks,