Did you try
vSeeds.push_back(CDNSSeedData("alexykot.me", "testnet-seed.alexykot.me"));
vSeeds.push_back(CDNSSeedData("bitcoin.petertodd.org", "testnet-seed.bitcoin.petertodd.org"));
vSeeds.push_back(CDNSSeedData("bluematt.me", "testnet-seed.bluematt.me"));
vSeeds.push_back(CDNSSeedData("bitcoin.schildbach.de", "testnet-seed.bitcoin.schildbach.de"));
bluematt used to work for me.