invalid asset amount errors due to ( float -> string) casting problems

[valzav]

[dnotestein]

Also, as a related issue, when this bug occurs, the balance reported by the GUI diverges from the balance reported from the console for the account (presumably the GUI keeps its own balance value and decrements it without verifying the order was successfully placed).

[vikramrajkumar]

Still happening in some cases: https://bitsharestalk.org/index.php/topic,15900.msg205125.html#msg205125