Since a couple of days ago etology started to pay very low CPM for popunders (for all publishers as far as I know). And fpctraffic popunder script is fucked up (it is more like a fullscreen popup script than a popunder script).
Are there any other brokers that can sell popunders for you?
My approach is to sell them directly now:
http://www.gfy.com/sell-and-buy-forum/966247-selling-popunder-spots-delivers-60000-uniques-day.html