diff -urN program.orig/lib/Roundcube/rcube_vcard.php program/lib/Roundcube/rcube_vcard.php
--- program.orig/lib/Roundcube/rcube_vcard.php	2013-10-21 22:39:20.000000000 +0300
+++ program/lib/Roundcube/rcube_vcard.php	2013-11-16 02:13:05.000000000 +0200
@@ -871,6 +871,49 @@
      */
     private static function detect_encoding($string)
     {
+        if (substr($string, 0, 4) == "\0\0\xFE\xFF") return 'UTF-32BE';  // Big Endian
+        if (substr($string, 0, 4) == "\xFF\xFE\0\0") return 'UTF-32LE';  // Little Endian
+        if (substr($string, 0, 2) == "\xFE\xFF")     return 'UTF-16BE';  // Big Endian
+        if (substr($string, 0, 2) == "\xFF\xFE")     return 'UTF-16LE';  // Little Endian
+        if (substr($string, 0, 3) == "\xEF\xBB\xBF") return 'UTF-8';
+
+        // heuristics
+        if ($string[0] == "\0" && $string[1] == "\0" && $string[2] == "\0" && $string[3] != "\0") return 'UTF-32BE';
+        if ($string[0] != "\0" && $string[1] == "\0" && $string[2] == "\0" && $string[3] == "\0") return 'UTF-32LE';
+        if ($string[0] == "\0" && $string[1] != "\0" && $string[2] == "\0" && $string[3] != "\0") return 'UTF-16BE';
+        if ($string[0] != "\0" && $string[1] == "\0" && $string[2] != "\0" && $string[3] == "\0") return 'UTF-16LE';
+
+        $rcube    = rcube::get_instance();
+        $language = $rcube->get_user_language();
+
+        //
+        // mb_detect_encoding can not correctly identify russian charsets
+        //
+        // Use this charset as fallback for vcard decoding
+        // $rcmail_config['default_vcard_charset'] = 'WINDOWS-1251';
+        //
+
+        if (($language == 'ru_RU') and (function_exists('iconv'))) {
+            $fallback = strtoupper(rcube::get_instance()->config->get('default_vcard_charset', 'WINDOWS-1251'));
+            $encodings = array('UTF-8', 'WINDOWS-1251', 'KOI8-R');
+            if (!in_array($fallback, $encodings)) $encodings[] = $fallback;
+
+            $res = array();
+            foreach ($encodings as $encoding) {
+                $sample = iconv($encoding, $encoding, $string);
+                if (md5($sample) == md5($string)) {
+                    $sample = iconv($encoding, 'UTF-8', $string);
+                    $sample = iconv('UTF-8', $encoding, $sample);
+                    if (md5($sample) == md5($string)) $res[] = $encoding;
+                }
+            }
+
+            if (count($res) == 1) {
+                return($res[0]);
+            } elseif (count($res) > 1) {
+                if (in_array($fallback, $res)) return($fallback);
+            }
+        }
         $fallback = rcube::get_instance()->config->get('default_charset', 'ISO-8859-1'); // fallback to Latin-1
 
         return rcube_charset::detect($string, $fallback);