This happens often when the template of the original page/feed does not include the proper header tag for an HTML browser to display characters correctly.

An html browser needs the following header tag in the original document, to enable displaying of non english charactors correctly; if they are of the proper character set.

<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />

Without the header tag in the original feed as a standard template, to be compatible with an html browser; the browser may/will not display the proper character set.

You may have to parse all incoming feeds, to include the header tag. Look through the support documents for your feed reader app, see if there's some option to set the character template to utf-8, or iso-something or other.

To parse incoming feeds you will need a feed parser. I have not used these, so I can't recommend a particular app, or provide valid instructions on how to use them with your feeds.

Try searching for a feedparser via google or yahoo search engines, read through the results and see if one might suite your needs etc..