6748 multicast not working?

Hi, I have been trying to get multicast to work on a C6748 platform, but I can not get the receive side working.  

I can see the RXMBPENABLE, MACHASH1, MACHASH2 been setup OK, since we have other 6472 unit, the EMAC registers are setup same way. But the hardware sees no the packet (the multicast count in the EMAC RXMCASTFRAMES does not change at all).

Thanks a lot,

Michael