[Plugin: WP-PostRatings] Problems with characters display on UTF-8 pages

When I solved one problem with wp-postratings widget 1.31

(the widget didnt display at all on UTF-8 pages – BTW the solution is here: https://lesterchan.net/wordpress/2008/06/09/warning-cannot-yet-handle-mbcs-in-html_entity_decode/)
another problem appeared.

The widget works, but does not display some non-english characters from post titles correctly. The page itself is in UTF-8 and displays Czech language text.

Any suggestions what to change in php code? Example: https://www.senftenberg.cz