TextField/TextArea, on input method composing text, the cursor doesn't move when pressing arrow keys.

JavaFX2.0 b44
Steps to reproduce:
1. create an app contains TextField or TextArea,
2. run the app on non-en Windows that Asian IM is installed,
3. invoke Asian IM, type something, the composing text is displayed, the cursor is at the end of composing text.
4. now press "Left" key

Bug: the cursor should move to left. But it's till at the end of composing text.
IM active client need to handle the cursor for composing text.

Snapshot video is attached.