Replying to [comment:5 scott.gonzalez]:
We need the specific steps to reproduce this. Please see #5933, which this is likely a duplicate of, for an example of the type of instructions we need in order to investigate this.
That's a similar issue but this is a different problem.
This is a test steps with Korean IME. (How to write 강남. It means Gangnam :-))
1. Install Korean IME (refer this link : http://www.declan-software.com/korean_ime/)
2. Visit http://jsfiddle.net/hmarM/17/ and put a cursor in the text field. :-)
3. Select Korean from the IME task bar. (refer link of 1.)
4. Press "r" -> ㄱ
5. Press "k" -> 가
6. Press "d" -> 강
7. Press "s" -> ㄴ
8. Press "k" -> 나
9. Press "a" -> 남 (there is a underline in this character)
10. Press arrow down.
Then you can see what's the problem.
Before 10th step, if you press arrow right and then do 10th step(press arrow down), then the underline is gone and it works right way.