TrafficStars Popunder: Over-concentration on single high-bid sites?

[Danny12345]

Is anyone else seeing traffic distribution issues with TrafficStars popunders,
where volume is heavily skewed toward a single publisher?

What's odd is that the winning bid for this specific site is significantly higher.
For instance, I know [boylove.cc] generates substantial volume at a lower CPM,

yet the lion's share of my traffic is being swallowed up by [missav.com] (which is high-traffic, but