A couple of pointers:
1) The stats issue is part of the reason I highly recommend setting up a html redirect for your parked pages. It allows you to control your own popups, and gives you great info about the source of your traffic (Like hvbo.com for me, I have my sedo listing popup in the background in addition to the DS ads. Then every hit is recorded in the server stats, allowing me to see the referral of the visitor or if they were a type-in, and allows an independant audit of the parking services stats).
2) I'm surprised DH is below Sedo for you. Sedo is currently my last place performer despite it having the some "high quality" domains parked there. (1% CTR for viewlaw.com, for instance. 45% CTR for XELaw.com at DS (stats from month to date) ).
-Allan