diff --git a/Classes/PHPExcel/Shared/String.php b/Classes/PHPExcel/Shared/String.php
index 3e495e8..31e2ef3 100644
--- a/Classes/PHPExcel/Shared/String.php
+++ b/Classes/PHPExcel/Shared/String.php
@@ -482,7 +482,7 @@ class PHPExcel_Shared_String
 	}
 
 	/**
-	 * Convert string from one encoding to another. First try iconv, then mbstring, or no convertion
+	 * Convert string from one encoding to another. First try mbstring, then iconv, finally strlen
 	 *
 	 * @param string $value
 	 * @param string $to Encoding to convert to, e.g. 'UTF-8'
@@ -491,14 +491,14 @@ class PHPExcel_Shared_String
 	 */
 	public static function ConvertEncoding($value, $to, $from)
 	{
-		if (self::getIsIconvEnabled()) {
-			return iconv($from, $to, $value);
-		}
-
 		if (self::getIsMbstringEnabled()) {
 			return mb_convert_encoding($value, $to, $from);
 		}
 
+		if (self::getIsIconvEnabled()) {
+			return iconv($from, $to, $value);
+		}
+
 		if($from == 'UTF-16LE'){
 			return self::utf16_decode($value, false);
 		}else if($from == 'UTF-16BE'){
@@ -548,20 +548,20 @@ class PHPExcel_Shared_String
 	 */
 	public static function CountCharacters($value, $enc = 'UTF-8')
 	{
-		if (self::getIsIconvEnabled()) {
-			return iconv_strlen($value, $enc);
-		}
-
 		if (self::getIsMbstringEnabled()) {
 			return mb_strlen($value, $enc);
 		}
 
+		if (self::getIsIconvEnabled()) {
+			return iconv_strlen($value, $enc);
+		}
+
 		// else strlen
 		return strlen($value);
 	}
 
 	/**
-	 * Get a substring of a UTF-8 encoded string
+	 * Get a substring of a UTF-8 encoded string. First try mbstring, then iconv, finally strlen
 	 *
 	 * @param string $pValue UTF-8 encoded string
 	 * @param int $start Start offset
@@ -570,14 +570,14 @@ class PHPExcel_Shared_String
 	 */
 	public static function Substring($pValue = '', $pStart = 0, $pLength = 0)
 	{
-		if (self::getIsIconvEnabled()) {
-			return iconv_substr($pValue, $pStart, $pLength, 'UTF-8');
-		}
-
 		if (self::getIsMbstringEnabled()) {
 			return mb_substr($pValue, $pStart, $pLength, 'UTF-8');
 		}
 
+		if (self::getIsIconvEnabled()) {
+			return iconv_substr($pValue, $pStart, $pLength, 'UTF-8');
+		}
+
 		// else substr
 		return substr($pValue, $pStart, $pLength);
 	}