$param = base64_decode($_REQUEST['param']);	
$param_mas = explode("\r\n",$param);
var_dump($param_mas);

$file_name = mysql_real_escape_string($param_mas[0]);
$file_id;
echo "<br>checking filename...: ".$file_name;
	
$query = "SELECT f_id FROM files WHERE f_filename='".$file_name."'";		
$query_result = mysql_query($query);	
if (mysql_num_rows($query_result) == 0)
{
    echo "<br>inserting new file...: ".$file_name;
    $query = "INSERT INTO files (f_first_letter, f_filename, f_text) VALUES('".strtoupper($file_name[0])."','".mysql_real_escape_string($file_name)."','')";
		
    if (mysql_query($query))
    {
        $query = "SELECT LAST_INSERT_ID()";		
	$query_result = mysql_query($query);
	$file_id = mysql_result($query_result, 0, 0);
    }
    else
        echo "<br>SQL-ERROR: ".mysql_errno()." - ".mysql_error();
}

$param = 'µрёрµҐ ±іАы°ьё® Б¦°Е911.LNK*new';
$param_mas = explode("*",$param);

if (!mysql_connect('localhost','test','')) 
{
    echo "Ошибка подключения к серверу MySQL\n";
    exit;
}
		
if (!mysql_select_db('test'))
...

$query = "INSERT INTO files (f_first_letter, f_filename, f_text) VALUES('".strtoupper($file_name[0])."','".$file_name."','')";		
echo "<br>".$query;
		
if (!mysql_query($query))
echo "<br>".mysql_error();

$file_name = 'µрёрµҐ ±іАы°ьё® Б¦°Е001.LNK';
$query = "INSERT INTO files (f_first_letter, f_filename, f_text) VALUES('".strtoupper($file_name[0])."','".$file_name."','')";		
echo "<br>".$query;
		
if (!mysql_query($query))
echo "<br>".mysql_error();

$file_name = $param_mas[0];

$file_name = 'µрёрµҐ ±іАы°ьё® Б¦°Е001.LNK';

$file_name = $param_mas[0];

$file_name = $param_mas[0];
var_dump($file_name);
//string(24) "µрёрµҐ ±іАы°ьё® Б¦°Е.LNK"

$file_name = 'µрёрµҐ ±іАы°ьё® Б¦°Е002.LNK';
var_dump($file_name);
//string(45) "µрёрµҐ ±іАы°ьё® Б¦°Е002.LNK" 

mysql_set_charset('utf8');

mysql_query ("set_client='utf8'");
mysql_query ("set character_set_results='utf8'");
mysql_query ("set collation_connection='utf8_general_ci'");
mysql_query ("SET NAMES utf8");