Search with non ascii character fails


I understand that you support Unicode characters in keyword search. However, I have a feed with problems. http://service.openkapow.com/ppow/japanese.rss
You can see that in the latest article, there is this text ?? but searching on this keyword from within feedreader does not return the article.
I have no trouble searching for Japanese words in other feeds, but this one gives me trouble. Is it due to the fact that the Japanese text in inside some html code inside the body of the article. Is it a Unicode problem somewhere?

??

??

This forum does not support Unicode

I cannot post Unicode characters in this forum, hence the ?? in my previous posts. Anyway, you can try the search with any word from an article from the feed mentionned above. It will not return any result, which looks to me like a bug of feedreader.