hi buddy,
this is my rotocoin.conf and it works, may it helps.
rpcuser=yourusername
rpcpassword=yourpassword
server=1
addnode=81.202.207.165
addnode=193.242.149.63
addnode=75.80.57.254
addnode=188.122.8.155
addnode=119.125.74.66
addnode=79.136.49.122
addnode=79.148.64.229