I'm using drupal 7, I create a page views with Filter criteria : Content: Title (exposed). when i type in the search bar, the title character is find the correct filter results. Only with the letter "Đ" filter is not understood.

Example:
I type "Đi hoc" then filter results find correct. But I typed "Di Hoc" is not the result. (page link like: http://domain.com/pagename?title=Đi+hoc)

Help me ! (sorry for my english)