What's problem? Only boooo's in minerd. Mining from wallet works well.
./minerd -o http://**********:31520 -u yourusername -p yourpasswordlongpassword33 -q
dropcoin.conf:
usepok=0
daemon=1
server=1
rpcuser=yourusername
rpcpassword=yourpasswordlongpassword33
rpcallowip=*.*.*.*
rpcport=31520
result:
[2015-05-31 12:18:49] 12 miner threads started, using 'drop' algorithm.
[2015-05-31 13:29:47] accepted: 0/1 (0.00%), 9.69 khash/s (booooo)