I run 2 clients on my 2 linux pc and this morning I found they have different blockchain_head_block_num. 
Mine is stuck on block count 751. May be it is the bug mentioned by bytemaster.
This may be also the reason I did not receive the fund yet. 
{
  "blockchain_head_block_num": 751,
  "blockchain_head_block_time": "20140613T083415",
  "blockchain_confirmation_requirement": 290,
  "blockchain_average_delegate_participation": 18.718843469591228,
  "network_num_connections": 0,
  "wallet_unlocked_seconds_remaining": 2892292014,
  "wallet_next_block_production_time": null,
  "wallet_seconds_until_next_block_production": null,
  "wallet_local_time": "20140613T160121",
  "blockchain_random_seed": "5ca9a6ed6ca1850ae6b01ab46e935390bc701e39",
  "blockchain_shares": 9999962538849,
  "network_num_connections_max": 12,
  "network_protocol_version": 101,
  "wallet_open": true,
  "wallet_unlocked_until": "19691231T235959",
  "wallet_version": 100
}