In the function get_links_list() headings for the Link categories are made by reading them from database, if the link category is named in complex scripts like Hindi then it outputs the name correctly but misses the id name in id attribute. For example see below, id="" is how it comes.
<li id="">à¤…à¤¨à¥?à¤¯ à¤¹à¤¿à¤¨à¥?à¤¦à¥€ à¤šà¤¿à¤Ÿà¥?à¤ à¥‡
This breaks the webpage's XHTML compliance.
In English calendar on the WP page days at the month top come as S M T W T F S. But this logic fails for other languages as Tuesday and Thursday might not start with the same letter. Similarly Sanday and Saturday. You can see this on my example hindi site at http://pnarula.com/wpd