In a Combox, when you enter some characters, it will filter the list of items automatically for you when you are typing. For example, when you type "j", all items which contain "j" will appear in the list. Everything works so far until you need to type some character of Chinese with an input method. For example, when you try to input "脚" (which means foot in English), you need to input "jiao" (the Pinyin of "脚") within the input method. And something strange starts happening: the Combox will capture the first "j" and make it the first character in the Combox, and will still let "jiao" continue to get "脚", and the final content in the Combox is "j脚", but what we expect is "脚" only. 

It seems like a defect.