One more tweak...
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 427e62f..643aecb 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -690,14 +690,16 @@
 		// We look for the prefix lang: to determine this

 		if (substr($fieldname, 0, 5) == 'lang:')

 		{

+			// Grab the variable

 			$line = substr($fieldname, 5);

-			

+

+			// Translate it

 			$fieldname = $this->CI->lang->line($line);

 			

 			// Were we able to translate the field name?

 			if ($fieldname === FALSE)

 			{

-				return $this->CI->lang->line($line);

+				return $line;

 			}

 			else

 			{