I cancelled my subscription last month because a lot of the sites were deindexed. Not sure if they fixed it already, but according to their support, they don't have any control on websites that do not belong to their own network.
So, if you are still a member and receiving trackbacks from deindexed domain, you can report those deindexed domain to help them. However, for me...it's just hassle, so I cancelled. It never worked well for me post penguin.
Maybe good to backlink your Tier 1, as suggested above.