That's the IGMP proxy looking for multicast members. I guess they don't actually disable the daemon down when you change the setting. Typical of the buggy garbage in that firmware.
que_ball: No you don't need the IGMP proxy on to use Optik TV, I've tried it with it on and with it off. It worked both ways for me so it may have been something else. That setting translates the addresses in the IGMP join messages, which is completely pointless if the Actiontec isn't doing NAT.