1267 Illegal mix of collations

When I try to search through my site and I put a character like ąźćę etc it gives me following output:

how to fix that?

site\parse.php:124
by default string searches in mysql are case insensitive so this conversion is not needed and moreover is causing problems. one should stick to utf8_general_ci and don't worry about that.

if it is opensource I would send You a patch
$query = "SELECT * FROM #__sef_redirect WHERE source=".$db->Quote($requested_uri)." AND published='1' LIMIT 1";