Things haven't been so smooth over there for awhile now. I got a friend who is having payment issues with them as well right now. Just swap their ads out for someone else. Try DatingGold or AFF. Nothing speaks louder than a loss of traffic from an affiliate. They do want to keep all their affiliates at any measures (so they say) but they also hum and haw about responding until it's too late.
Maybe you should give them a call?
http://www.whois.sc/cashring.com