Apostrophy replaced with box in UTF-8 encoding


As per title. First, you must use the latest 3.12 version of Feedreader and edit .ini file like this (because the feed takes a long time to return something):
[misc]
httpConnectionTimeout=300
httpReadTimeout=320

Then, add this feed:
http://service.openkapow.com/ppow/rmfqe?max=60&rssVersion=2.0&channelName=&channelLink=&channelImageURL=&channelDescription=

Feed item bodies have some html code, encoded in UTF-8. You can see that some Apostrophes are replaced with boxes (exemple: feed item "Du grain à moudre 2008-01-16"). I understand that the apostrophe is not the (ugly) ASCII apostrophe, but a more elegant Unicode apostrophe (code U+2019). Anyhow, the trouble is that this apostrophe is replaced by a box in Feedreader.

First, I thought it was an issue with the feed itself, but I tried in Opera and IE, and both show apostrophes (although Opera shows the "ugly" type Apostrophe) Could Feedreader do the same and display apostrophes, not boxes?

à replaced with ..

An other issue in the same feed is that à is replaced with á (accent pointing to the right, but it is not the same).
I even changed the font in atom.xsl but same problem. Why does Feedreader change the original characters? What should I do to display the original characters?