Multicast over IPSec VPN

Hi,

I am having trouble getting the multicast working over IPSec site to site VPN.

The topology is:

RoIP > Cisco Router > Fortigate  >> IPSec >> Fortigate >> Cisco Router >> RoIP

I have followed the KB and had Fortigate support verify the settings are correct. I have PIM Sparse-mode enabled on all devices and interfaces that are involved in the multicast communication. I can ping both RoIP units and the multicast RP over the tunnel - no issues there. But for some reason the traffic is not traversing over the tunnel.

Was wondering if anyone else tried to get multicast working over the IPSec?

Thanks