Big posts becomes empty if they have smilies on specified places, and then shows error "Your message is too short". That occures with non-english symbols also. I haven't revealed exact regularity of bug appearance. In one cases it works, in others not, as test file that i attached below. This test message contains about 55000 symbols and Exclamation smilie at the very beginning of the message.
Smiles placed right at the beginning is not mandatory, it's just for example. At some places all works fine, but not at others.