Another problem I found using brainwallet is that it creates bad transactions, for instance the one that I pushed took more than 10 hours to get confirmed (I thought it would never confirm) because instead of sending the full amount (like I told it to do) brainwallet deducted 1 satoshi from the transaction which resulted in sending that 1 satoshi back to the sender's address and then I got this warning in blockchain explorer "This transaction has a very small output and is none standard" even though it did had 0.0001 Tx fee.
You should review your transaction before pushing it. Read 'JSON Transaction' field and you will see details. After you verify, correct if there is any mistakes/errors and then push transaction.
