Arabic charcter in links

hello I am getting theses lines in my apache logs
ALERT - configured GET variable value length limit exceeded - dropped variable ‘urlref’ (attacker ‘’, file ‘/xxx/piwik.php’), referer: video sharing music hits news people trailers fun football sports
is this because there arabic chacters in url ?

Check your Suhosin configuration.

thank u for your reply , but can you give me more details , i don’t know what to change or to do?