Weird, but strtr corrupting chars, if used like below and if file is encoded in UTF-8;

<?php
$str = 'Äbc Äbc';
echo strtr($str, 'Ä', 'a');
// output: a�bc a�bc
?>

And a simple solution;

<?php
function strtr_unicode($str, $a = null, $b = null) {
    $translate = $a;
    if (!is_array($a) && !is_array($b)) {
        $a = (array) $a;
        $b = (array) $b;
        $translate = array_combine(
            array_values($a),
            array_values($b)
        );
    }
    // again weird, but accepts an array in this case
    return strtr($str, $translate);
}

$str = 'Äbc Äbc';
echo strtr($str, 'Ä', 'a') ."\n";
echo strtr_unicode($str, 'Ä', 'a') ."\n";
echo strtr_unicode($str, array('Ä' => 'a')) ."\n";
// outputs
// a�bc a�bc
// abc abc
// abc abc
?>