If an amount is shown in the "stake" column then this means your wallet is in the process of trying to mint a block and earn the staking reward with those coins. They are temporarily unspendable during this time, which I believe lasts 32 bocks (someone please correct me if I am wrong).

If you want to prevent your coins from staking then enter 'reservebalance=1000000' in your emercoin.conf file and restart the client.

Otherwise just be patient until they finish trying to stake and you will be ale to send them again.

see https://wiki.emercoin.com/en/Emercoin_PoS_minting