How can I make correct this character conversion

Hello I tried two plugins but I got the same error. Those plugins converts the cyrillic characters used in the post slug into latin chars.
However the result is like “aaaaaiaaaaa” and other similar.
Those are the two plugins :
Any help is appreciated

add_filter('name_save_pre', 'cyr_slugs', 0);

function cyr_slugs($slug) {
    $cyrillic = array('?','α','β','γ','δ','ε','ζ','η','θ','ι','κ','λ','μ','ν','ξ','ο','π','ρ','?','σ','τ','υ','φ','χ','ψ','ω','?','?','?','?','?','?');
    $translit = array('a','b','v','g','d','e','zh','z','i','i','k','l','m','n','o','p','r','s','t','u','f','h','c','ch','sh','sht','u','y','y','e','yu','ya');

    // We don't want to change an existing slug
	if ($slug) return $slug;

	global $wpdb;
	$cyr_slug = cyr_strtolower(strtolower(stripslashes($_POST['post_title'])));
	$cyr_slug = str_replace($cyrillic, $translit, $cyr_slug);
	$cyr_slug = str_replace(" ", "-", $cyr_slug);

	return $cyr_slug;
}

function cyr_strtolower($a) {
	// Just in case standard strtolower doesn't work
        $offset=32;
        $m=array();
        for($i=192;$i<224;$i++)$m[chr($i)]=chr($i+$offset);
        return strtr($a,$m);
}
?>

class Cyr2LatSlug
{
	var $translit_table = array(
	"?"=>'a',
	"α"=>'b',
	"β"=>'v',
	"γ"=>'g',
	"δ"=>'d',
	"ε"=>'e',
	"ζ"=>'zh',
	"η"=>'z',
	"θ"=>'i',
	"ι"=>'j',
	"κ"=>'k',
	"λ"=>'l',
	"μ"=>'m',
	"ν"=>'n',
	"ξ"=>'o',
	"ο"=>'p',
	"π"=>'r',
	"ρ"=>'s',
	"?"=>'t',
	"σ"=>'u',
	"τ"=>'f',
	"υ"=>'h',
	"φ"=>'c',
	"χ"=>'ch',
	"ψ"=>'sh',
	"ω"=>'sch',
	"?"=>'',
	"?"=>'y',
	"?"=>'',
	"?"=>'e',
	"?"=>'yu',
	"?"=>'ya',
	"?"=>'e',
	"?"=>'g',
	"?"=>"e",
	"?"=>'yi',
	"3"=>'i',
	"¨"=>'e',
	"￥"=>'g',
	"?"=>"e",
	"―"=>'yi',
	"2"=>'i',
	" "=>'-');

	function Cyr2LatSlug() {
		add_filter('name_save_pre', array(&$this, 'doCyr2LatSlug'), 1);
	}

	function doCyr2LatSlug($slug) {
		global $wpdb;
		//setlocale(LC_ALL, 'en_US.UTF8');

	    // We don't want to change an existing slug
		if (!empty($slug)) {return $slug;}

		$s = trim($_POST['post_title']);
		$s = iconv('utf-8', 'windows-1251', $s);
		//$s = mb_strtolower($s, 'windows-1251');
		$s = $this->cyr_strtolower(strtolower(stripslashes($s)));
		$s = strtr($s, $this->translit_table);
		return $s;
	}

	function cyr_strtolower($a) {
		// Just in case standard strtolower doesn't work
		// this function is written by Petko Bossakov
		$offset=32;
		$m=array();
		for($i=192;$i<224;$i++){$m[chr($i)]=chr($i+$offset);}
		return strtr($a,$m);
	}
}
$Cyr2LatSlug = new Cyr2LatSlug();
?>