Bitcoin Plus - XBC is a Proof of Stake Coin. As soon as coins are in your wallet and mature (24 hours) they start to 'Stake'. During the process coins will move from Spendable to Stake inside the XBC Wallet. Only the Spendable amount can be sent from the wallet. This can be a pain when you want to send some XBC to an exchange and find that you cant because the coins are 'locked in'.
There is a feature in the Bitcoin Plus Wallet that allows you to reserve some coins so that they will always remain on reserve and available. See Screenshots below on how to set this feature up.