diff --git a/importexport/inc/class.importexport_import_ui.inc.php b/importexport/inc/class.importexport_import_ui.inc.php
index f2b31e1aed..fbddedb6bd 100644
--- a/importexport/inc/class.importexport_import_ui.inc.php
+++ b/importexport/inc/class.importexport_import_ui.inc.php
@@ -71,7 +71,7 @@
 						$preference = $GLOBALS['egw_info']['user']['preferences']['common']['csv_charset'];
 					}
 					$required = $options['charset'] == 'user' || !$options['charset'] ? $preference : $options['charset'];
-					$encoding = translation::detect_encoding($sample);
+					$encoding = translation::detect_encoding($sample, $required);
 					if($encoding && strtoupper($required) != strtoupper($encoding))
 					{
 						$this->message = lang("Encoding mismatch.  Expected %1 file, you uploaded %2.<br />\n",
@@ -79,7 +79,7 @@
 							$encoding
 						);
 					}
-					
+
 					$file = fopen($content['file']['tmp_name'], 'rb');
 					$count = 0;
 
@@ -158,7 +158,7 @@
 							'import_'.md5($content['file']['name'].$GLOBALS['egw_info']['user']['account_id'])));
 						unset($dst_file);
 					}
-					
+
 				} catch (Exception $e) {
 					$this->message .= $e->getMessage();
 				}
diff --git a/phpgwapi/inc/class.translation.inc.php b/phpgwapi/inc/class.translation.inc.php
index 28279168e7..0737e899a7 100644
--- a/phpgwapi/inc/class.translation.inc.php
+++ b/phpgwapi/inc/class.translation.inc.php
@@ -838,20 +838,37 @@ class translation
  	/**
 	 * detect_encoding - try to detect the encoding
 	 *    only to be used if the string in question has no structure that determines his encoding
+	 *
 	 * @param string - to be evaluated
+	 * @param string $verify=null encoding to verify, get checked first and have a match for only ascii or no detection available
 	 * @return string - encoding
 	 */
-	static function detect_encoding($string) {
-		static $list = array('utf-8', 'iso-8859-1', 'windows-1251'); // list may be extended
+	static function detect_encoding($string, $verify=null)
+	{
 		if (function_exists('iconv'))
 		{
-			foreach ($list as $item) {
+			$list = array('utf-8', 'iso-8859-1', 'windows-1251'); // list may be extended
+
+			if ($verify) array_unshift($list, $verify);
+
+			foreach ($list as $item)
+			{
 				$sample = iconv($item, $item, $string);
-				if (md5($sample) == md5($string))
+				if ($sample == $string)
+				{
 					return $item;
+				}
 			}
 		}
-		return self::$mbstring ? strtolower(mb_detect_encoding($string)) : 'iso-8859-1'; // we choose to return iso-8859-1 as default
+		if (self::$mbstring)
+		{
+			$detected = strtolower(mb_detect_encoding($string));
+		}
+		if ($verify && (!isset($detected) || $detected === 'ascii'))
+		{
+			return $verify;	// ascii matches all charsets
+		}
+		return isset($detected) ? $detected : 'iso-8859-1'; // we choose to return iso-8859-1 as default
 	}
 
 	/**