there is a bug in both 6.3 and 6.4 under IE6,IE7,IE8 compatible mode ,it can be reproduced in online demo.
You guys are simply input English letters using this editor and it's perfect,but I have to input some Chinese characters. When I using a Chinese IME too input Chinese Characters(such as Microsoft Pinyin IME, Intelligent ABC - very famous IME),the first character cannot be input in the editor. Only after I input a English letter or an "enter" the Chinese character can now be input in the editor.

 

Are there any Chinese staff in your company? you can let them test.Thank you and sorry for my poor English.