BUG: adding emoticons will clear all?

Just now , I tested this prob in Sleipnir, and the chance of characters got cleared is slimmer than GreenBrowser,but it still some times exists. I noticed a strange things: when I typed something and insert an emoticon, SOMETIMES the typing cursor went to the beginning of the whole textarea,but the emoticon code was successfuly inserted. After that, if I type more, the coming letter will be at the the very beginning. Does the new non-RTE post editor do something new with the handling of focus?